Appendix C. Commands and Flags

This appendix provides a list of many (but certainly not all) Unix commands and programs as well as many of the related command-line flags.

In general, flags offer a thorough selection of options for programs that operate exclusively from command-line input, as well as an overview of the functionality for many other programs. Please keep in mind, however, that command flags only touch the surface of the capabilities of interactive programs (like pico, vi, links, or pine) or particularly complex programs that rely on special expressions (such as grep or tr) or that use multiple files or sources for information (such as procmail).

Table C.1 should provide you with a brief reminder and starting point for learning more about these Unix commands. While the flags we’ve included here work on our systems, they will likely vary somewhat on different systems, different Unix versions or with different shells. Check your local man pages for specifics.

Table C.1. Commands and Flags

COMMAND/FLAG	DESCRIPTION
alias	Use to create command aliases.
at	Use to schedule, examine, or delete jobs for queued execution.
-V	Displays version information.
-q queue	Specifies queue to use (as a letter). Higher letters are nicer.
-m	Specifies mail notification to user when job has completed.
-f file	Reads job from file.
-l	Lists queues, just like atq.
-d	Deletes scheduled jobs, just like atrm.
atq	Use to show queues of scheduled jobs.
-q queue	Specifies queue to use (as a letter).
atrm	Use to remove a job from the queue.
-q queue	Specifies queue to use (as a letter).
awk	Use to manipulate files as databases.
-F fieldseparator	Specifies field separator.
-v variable=value	Sets variable to value.
-f program -file	Specifies file or files containing awk program source.
--help	Prints help information.
--version	Prints version information.
--	Specifies end of option list.
bash	Use the efficient, user-friendly shell bash.
-c string	Reads commands from string.
-i	Makes the shell interactive, as opposed to noninteractive, as in a shell script.
-s	Specifies that additional options, beyond those given, should be read from standard input.
-, --	Indicates the end of options and stops further option processing.
--norc	Specifies not to read ~/.bashrc.
--noprofile	Specifies not to read systemwide or individual configuration files.
--rcfile file	Specifies alternative configuration file.
--version	Displays bash version number.
--login	Specifies to start bash as a login shell.
--posix	Specifies Posix compliance, which helps make anything more portable from system to system.
batch	Use to schedule jobs for low system loads.
bg	Use to move a job to the background.
cal	Use to display a calendar.
-j	Displays Julian dates with days numbered through the year from January 1.
-y	Displays the current year’s calendar.
month year	Specifies month (1 to 12) and year (1 to 9999).
cat	Use to send text to standard output, usually the screen.
-b, --number-nonblank	Specifies to number all nonblank output lines.
-n, --number	Specifies to number all output lines.
-s, --squeeze-blank	Specifies to replace adjacent blank lines with a single blank line.
-v, --show-nonprinting	Specifies to display control characters with “^” preceding them.
-A, --show-all	Specifies to show all control characters.
-E, --show-ends	Specifies to display a “$” at the end of each line.
-T, --show-tabs	Specifies to display tab characters as “^I”.
--help	Displays a help message.
--version	Displays the version number.
cd	Use to change the working directory.
chgrp	Use to change the group ownership of files.
-c, --changes	Specifies to list files whose ownership actually changes.
-f, --silent, --quiet	Suppresses error messages for files that cannot be changed.
-v, --verbose	Specifies to describe changed ownership.
-R, --recursive	Specifies to recursively change ownership of directories and contents.
--help	Displays help message.
--version	Displays version information.
chmod	Use to change the access permissions of files.
-c, --changes	Specifies to list files whose permissions actually change.
-f, --silent, --quiet	Suppresses error messages.
-v, --verbose	Specifies to describe changed permissions.
-R, --recursive	Specifies to recursively change permissions of directories and contents.
--help	Displays help message.
--version	Displays version information.
chown	Use to change the user and group ownership of files.
-c, --changes	Specifies to list files whose ownership actually changes.
-f, --silent, --quiet	Suppresses error messages for files that cannot be changed.
-v, --verbose	Specifies to describe changed ownership.
-R, --recursive	Specifies to recursively change ownership of directories and contents.
--help	Displays help message.
--version	Displays version information.
chsh	Use to change your login shell.
-s, --shell	Specifies the new login shell.
-l, --list-shells	Displays the shells in /etc/shells.
-u, --help	Prints a help message.
--version	Prints version information.
cmp	Use to compare two files.
-l	Displays the byte number (which starting byte in the file) in decimal and the differing bytes in octal for each difference.
-s	Displays nothing for differing files except exit status.
compress	Use to compress and expand archives.
-c	Specifies that compress/uncompress write to standard output (usually your screen) and leave files unchanged.
-r	Specifies to recursively process directories.
-V	Displays version information.
cp	Use to copy files or directories.
-a, --archive	Specifies to preserve file structure and attributes.
-b, --backup	Specifies to make backups of files before overwriting.
-d, --no-dereference	Specifies to copy symbolic links as symbolic links rather than the files that they point to.
-f, --force	Specifies to overwrite all existing destination files.
-i, --interactive	Requires prompting before overwriting.
-l, --link	Specifies to make hard links instead of copies of files.
-P, --parents	Completes destination filenames by appending the source filename to the target directory name.
-p, --preserve	Specifies to preserve the original file characteristics, including permissions and ownership.
-r	Specifies to copy directories recursively.
-s, --symbolic-link	Specifies to make symbolic links instead of copies of files.
-u, --update	Specifies not to overwrite newer files.
-v, --verbose	Displays filenames before copying.
-x, --one-file-system	Restricts action to a single file system.
-R, --recursive	Specifies to copy directories recursively.
--help	Prints a help message.
--version	Prints version information.
-S, --suffix backup-suffix	Specifies a suffix for backup files.
crontab	Use to maintain crontab files.
-l	Displays current crontab.
-r	Removes current crontab.
-e	Opens crontab in default editor.
df	Use to display information about free disk space.
-a, --all	Specifies that all file systems, including special ones (e.g. CDROM, MSDOS), should be processed.
-i, --inodes	Displays inode (disk element) usage information.
-k, --kilobytes	Displays sizes in 1 KB blocks instead of 512-byte blocks.
-h	Provides file sizes in human-readable format.
-P, --portability	Uses Posix standard output format.
-T, --print-type	Displays type of each file system.
-t, --type=fstype	Displays only named file system types.
-x, --exclude-type=fstype	Displays only non-named file system types.
--help	Prints help information.
--version	Prints version information.
diff	Use to display differences between text files.
-b	Specifies to ignore trailing blanks (spaces and tabs) and consider other blanks equivalent.
-i	Specifies case-insensitive comparisons.
-t	Specifies to expand tab characters to spaces in output.
-w	Specifies to ignore all blanks.
-c	Specifies a listing of differences with three lines of context.
-C number	Specifies a listing of differences with number lines of context.
-e	Specifies output of a script for the ed editor to re-create the second file from the first.
-f	Specifies output of a script to create the first file from the second. This does not work with ed.
-h	Specifies fast and not necessarily complete comparison.
-n	Specifies output of a script to create the first file from the second along with a total of changed lines for each command.
-D string	Outputs combined version of first and second files with C preprocessor controls to compile as the first or the second file.
-r	Specifies that diff should recursively process subdirectories common to both given directories.
-s	Outputs names of identical (not different) files.
-S name	Begins comparison within a directory with the specified filename.
dig	Use to look up IP numbers or domain names.
-b ip-address	Specifies to set the source IP address of the query.
-f filename	Specifies to read lookup requests from a file (filename).
-p portnumber	Specifies a port number to use instead of the standard 53.
-t type	Specifies the query type.
-x	Specifies reverse lookups (addresses to names).
du	Use to display disk usage information.
-a, --all	Displays information for all files.
-b, --bytes	Displays sizes in bytes.
-c, --total	Displays totals for all arguments.
-k, --kilobytes	Displays sizes in kilobytes.
-h, --human-readable	Provides file sizes in human-readable format.
-l, --count-links	Displays sizes of all files, including linked files counted elsewhere.
-s, --summarize	Displays only totals for each argument.
-x, --one-file-system	Specifies not to process directories on other file systems.
-L, --dereference	Displays space used by linked file or directory, not just space used by link.
-S, --separate-dirs	Counts directories separately.
--help	Prints help information.
--version	Prints version information.
elm	Use to send and receive mail.
-a	Specifies arrow cursor.
-c	Expands specified aliases and exits.
-d level	Specifies debugging output.
-f folder	Specifies folder to read instead of incoming mail folder.
-h, -?	Displays help message.
-i file	Read named file into message editor.
-m	Disables menu.
-s subj	Specifies subject for mail messages.
-v	Displays version information.
-z	Specifies not to start elm if no mail is present.
emacs	Use to edit files.
file	Specifies name of file to edit.
+number	Specifies to go to the specified line number.
-q	Specifies not to load an initialization file.
-u user	Specifies to load users’s initialization file.
-t file	Specifies to use file as the terminal.
expr	Use to evaluate expressions.
--help	Specifies to display help information.
--version	Specifies to display version information.
fg	Use to move a job to the foreground.
file	Use to determine file type.
-m list	Specifies alternative list of files with magic numbers (helping to indicate file type).
-z	Attempts to look into compressed files.
-b	Specifies brief output mode.
-c	Checks magic file.
-f file	Specifies to read names of the files to be examined from file.
-L	Specifies to follow symbolic links.
find	Use to find files in the Unix system.
-daystart	Specifies to measure all times starting today, not 24 hours ago.
-depth	Specifies to process directory contents before the directory.
-follow	Specifies to follow symbolic links.
-help, --help	Prints a help message.
-maxdepth levels	Specifies how many levels below starting directory level to descend.
-mindepth levels	Specifies how many levels below starting directory level to start processing.
-mount, -xdev	Specifies not to descend directories on other file systems.
-noleaf	Specifies not to optimize for Unix systems, which is needed for CD-ROM directories, for example.
--version	Prints version information.
-amin n	Finds files accessed n minutes ago.
-anewer file	Finds files accessed more recently than they were modified.
-atime n	Finds files accessed n days ago.
-cmin n	Finds files whose status was changed n minutes ago.
-cnewer file	Finds files whose status was changed more recently than the file was modified.
-ctime n	Finds files whose status was changed n days ago.
-empty	Finds files that are empty.
-fstype type	Finds files on file systems of specified type.
-gid n	Finds files with numeric group ID of n.
-group gname	Finds files with group name of gname or corresponding group ID.
-ilname pattern	Finds files that are symbolic links with pattern text in the name, case-insensitive.
-iname pattern	Finds files with pattern in the name, case-insensitive.
-inum n	Finds files with inode number n.
-ipath pattern	Finds files with pattern in the path, case-insensitive.
-iregex pattern	Finds files with regular expression pattern in name, case-insensitive.
-links n	Finds files with n links.
-lname pattern	Finds files that are symbolic links with pattern in the name.
-mmin n	Finds files last modified n minutes ago.
-mtime n	Finds files last modified n days ago.
-name pattern	Finds files with name of pattern.
-newer file	Finds files modified more recently than file.
-nouser	Finds files with no user name corresponding to the numeric userid.
-nogroup	Finds files with no group name corresponding to the numeric group ID.
-path pattern	Finds files with paths matching pattern.
-regex pattern	Finds files with regular expression pattern in name, case-sensitive.
-size n[bckw]	Finds files using n blocks, bytes, kilobytes, or words, respectively, of space.
-type type	Finds files of type type, where b is block (buffered) special, c is character (unbuffered) special, d is directory, p is named pipe (FIFO), f is regular file, l is symbolic link, or s is socket.
-uid n	Finds files with numeric userid of n.
-used n	Finds files last accessed n days after status changed.
-user uname	Finds files owned by userid or numeric id user ID.
-exec command ;	Executes command for each found file.
-fprint file	Prints full filename into file.
-ok command ;	Executes command with confirmation for each found file.
-print	Prints results to standard output.
finger	Use to display information about users.
-s	Displays the login name, real name, terminal name and write status, idle time, login time, office location, and office phone number.
-l	Specifies multiple-line format with information from -s option plus user’s home directory, home phone number, login shell, mail status, and the contents of the .plan, .project, and .forward files.
-p	Prevents -l from displaying contents of .plan and .project files.
-m	Disables matching user names.
fmt	Use to format files.
-c, --crown-margin	Specifies to preserve indent of first two lines.
-p, --prefix=chars	Specifies to combine lines with chars at the beginning.
-s, --split-only	Specifies to split long lines, but not to combine short ones.
-t, --tagged-paragraph	Specifies that the indent of the first line differs from the next.
-u, --uniform-spacing	Specifies to ensure one space between words, two after sentences.
-w, --width=n	Specifies a maximum line width (default of 75 chars).
--help	Specifies to display a usage message.
--version	Specifies to display version information.
ftp	Use to put files in or get files from FTP (File Transfer Protocol) archives.
-v	Specifies verbose output of responses and statistics.
-n	Restricts automatic log in.
-i	Turns off interactive prompting during multiple file transfers.
-d	Enables debugging output.
-g	Disables wildcards (“globbing”).
grep	Use to display lines matching a given pattern.
-n	Displays matches with n lines before and after matching lines.
-A n, --after-context=n	Displays matches with n lines after matching lines.
-B n, --before-context=n	Displays matches with n lines before matching lines.
-C, --context	Displays matches with two lines of surrounding context.
--version	Displays version information.
-c, --count	Displays count of matches for each file.
-e pattern, → --regexp=pattern	Specifies pattern explicitly.
-f file, --file=file	Reads patterns from file.
-h, --no-filename	Specifies not to display filenames in output.
-i, --ignore-case	Searches without regard to case.
-L, --files-without-match	Prints name of first nonmatching file.
-l, --files-with-matches	Prints name of first matching file.
-n, --line-number	Displays output line numbers.
-q, --quiet	Suppresses output and stops scanning on first match.
-s, --no messages	Suppresses error messages.
-v, --invert-match	Inverts matching to select opposite files.
-w, --word-regexp	Finds only matches for whole words.
-x, --line-regexp	Finds only matches for the whole line.
gzip	Use to compress (gzip) or expand files.
-a -ascii	Specifies to convert ends of lines in ASCII text mode to conform to Unix conventions.
-c --stdout --to-stdout	Sends output to standard output while maintaining original files unchanged.
-d --decompress → -uncompress	Uncompresses files.
-f -force	Forces compression or decompression.
-h -help	Displays help message.
-l -list	Lists information about compressed files.
--verbose	Displays additional information about archive files.
-L -license	Displays the gzip license.
-n --no-name	Specifies not to save the original filename and time.
-N -name	Specifies to always save the original filename and time-stamp information when compressing.
-q -quiet	Suppresses all warnings.
-r -recursive	Specifies to descend subdirectories.
-S .suf --suffix .suf	Specifies alternative suffixes.
-t -test	Tests compressed-file integrity.
-v -verbose	Displays name and percentage reductions for each file processed.
-V -version	Displays version information.
head	Use to output the first part of files.
-c, --bytes n[b,k,m]	Displays first n bytes of file, in b (512-byte blocks), k (1 KB blocks), or m (1 MB blocks).
-n N, --lines n	Displays first n lines of a file.
-q, --quiet, --silent	Specifies not to display filenames.
-v, --verbose	Displays filename.
--help	Displays help message.
--version	Displays version information.
id	Use to display real and effective userids and group IDs.
-g, --group	Displays only group ID.
-G, --groups	Displays only supplementary groups.
--help	Displays help message.
-n, --name	Displays user or group name, not number.
-r, --real	Displays real, not effective, userid or group ID.
-u, --user	Displays only userid.
--version	Displays version information.
jobs	Use to display list of jobs under control.
-l	Displays additional information (long listing) for jobs.
-p	Displays job process IDs.
-n	Displays jobs that have stopped or exited since notification. Only in ksh.
kill	Use to terminate a process.
-s	Specifies kill signal to send.
-l	Displays a list of signal names.
less	Use to page through files; similar to more.
-?, --help	Displays a command summary.
-a	Specifies to start searches below visible display.
-bn	Specifies number of buffers for each file.
-B	Specifies automatic buffer allocation.
-c	Specifies not to scroll, but rather to paint each screen from the top.
-C	Specifies not to scroll, but rather to clear and display new text.
-d	Suppresses error messages for dumb terminals.
-e	Specifies to automatically exit if you move down after hitting the end of the file.
-E	Specifies to automatically exit when you hit the end of the file.
-f	Forces all files to be opened.
-g	Specifies to highlight only last found string.
-G	Specifies no highlighting of found strings.
-hn	Specifies maximum number (n) of lines to scroll backward.
-i	Specifies case-insensitive searches except when search string contains capital letters.
-I	Specifies case-insensitive searches always.
-jn	Specifies a line on the screen where a target line should be located.
-k filename	Specifies to open and interpret filename as a lesskey file.
-m	Specifies verbose prompting, displaying percentage into the file viewed.
-M	Specifies even more verbose prompting.
-n	Suppresses line numbers.
-N	Specifies line number for each displayed line.
-ofilename	Tells less to copy input to filename as it is viewed.
-Ofilename	Tells less to copy input to filename as it is viewed and overwrite without confirmation.
-ppattern	Specifies to start display at first occurrence of pattern.
-q	Specifies quiet operation and only rings bell on certain errors.
-Q	Specifies totally quiet operation and never rings bell.
-r	Specifies to display control characters directly, even if display problems result.
-s	Compresses consecutive blank lines into a single blank line.
-S	Specifies that long lines should be chopped off, not wrapped.
-u	Specifies that backspaces and carriage returns should be sent to the terminal.
-U	Specifies that backspaces, tabs, and carriage returns should be treated as control characters.
-V, --version	Displays the version number.
-w	Specifies that blank lines, not tilde (~) represent lines after the end of the file.
-xn	Sets tab stops every n columns.
-X	Disables termcap initialization strings.
-yn	Specifies maximum number of lines to scroll.
-n	Specifies the scrolling window size as n.
-"	Specifies filename quoting character.
--	Indicates end of options.
links	Use to browse the Web in character-only mode, but with tables and frames.
-g	Specifies to run in graphics mode, on an appropriate terminal.
-async-dns n	Specifies to look up domain names as needed (0) or preemptively (1).
-max-connections n	Specifies the maximum number of concurrent Web connections.
-max-connections-to-host n	Specifies the maximum number of concurrent connections to a specific host.
-retries n	Specifies the number of retries to retrieve a Web page.
-receive-timeout n	Specifies the length (in seconds) of the timeout when retrieving a Web page.
-unrestartable-receive	Specifies the timeout on nonrestartable connections.
→ -timeout n
-format-cache-size n	Specifies the number of Web pages to cache for quicker retrieval.
-memory-cache-size n	Specifies the amount of cache memory in kilobytes.
-http-proxy name:n	Specifies the name and port number of the HTTP proxy, if needed.
-ftp-proxy name:n	Specifies the name and port number of the FTP proxy, if needed.
-download-dir path	Specifies the default download directory.
-anonymous	Specifies to restrict capabilities to run in an anonymous account.
-no-connect	Specifies to run links as a separate process instead of within an existing process.
-version	Specifies to display the version number.
-help	Specifies to print help information.
ln	Use to make links between files.
-b, --backup	Backs up files before removing them.
-f, --force	Overwrites destination files.
-i, --interactive	Prompts before overwriting files.
-n, --no-dereference	Attempts to replace symbolic links.
-s, --symbolic	Specifies to make symbolic links when possible.
-v, --verbose	Specifies to display filenames before linking.
--help	Prints a help message.
--version	Prints version information.
-S, --suffix backup-suffix	Specifies suffix for backup files.
-V, --version-control → {numbered, existing, simple}	Specifies version control as numbered, existing, or simple, as with cp.
locate	Use to find files with a specific string in their names or paths.
-u	Specifies to create locate database starting at the root directory.
-U path	Specifies to create locate database starting at path.
-e dir, dir, ...	Specifies to exclude directories from the locate database.
-f fstype	Specifies to exclude files on named file system types from the database.
-c	Specifies to process /etc/updatedb.conf file when updating the database.
-l n	Specifies the security level as 0 (no checking, faster), or 1 (checking, slower).
-i	Specifies to do a case-insensitive search.
-q	Specifies to use quiet mode and suppress all error messages.
-n n	Specifies to limit the amount of results shown to n.
-r regex, --regexp=regex	Specifies to search the database using a regular expression.
-o name, --output=name	Specifies the database to create.
-d path, --database=path	Specifies the path of databases to search in.
-h, --help	Specifies to print help information.
-v, --verbose	Specifies to use verbose mode when creating database.
-V, --version	Specifies to display the version number.
look	Use to look up words in the system dictionary.
-d	Specifies to use dictionary (alphanumeric) character set and order.
-f	Specifies to use case-insensitive search.
-a	Specifies to use the alternate dictionary /usr/share/dict/web2.
-t	Specifies the end of the string to compare.
lp	Use to print files.
-c	Specifies to copy file to spool directory before printing.
-d name	Specifies to print files to the printer name.
-i n	Specifies an existing job number n to modify.
-m	Specifies to send email when the job is completed.
-n copies	Specifies the number of copies to print.
-q priority	Specifies the job priority from 1 to 50 (highest).
-s	Specifies not to report the resulting job IDs.
-t name	Specifies the name for the job being submitted.
-H handling	Specifies immediate, hold, resume, or hh:mm to determine when the job will be printed.
-P page-list	Specifies which pages to print.
ls	Use to list directory contents.
-a, --all	Lists all files.
-b, --escape	Prints octal codes for nongraphic characters using backslash sequences.
-c, --time=ctime, → --time=status	Sorts according to status change time, not modification time.
-d, --directory	Lists directory names, not contents.
-f	Does not sort directory contents.
--full-time	Provides full, not abbreviated time listings.
-g	Displays filename, file permissions, number of hard links, group, size, and time.
-h	Provides file sizes in human-readable format.
-i, --inode	Displays index number of each file.
-k, --kilobytes	Displays file sizes in kilobytes.
-l, --format=long, → --format=verbose	Displays filename, file permissions, number of hard links, owner, group, size in bytes, and time.
-m, --format=commas	Displays names separated by commas.
-n, --numeric-uid-gid	Displays numeric userid and group ID.
-p, -F	Displays extra character for each filename to show the file type.
-q, --hide-control-chars	Displays question marks rather than nongraphic characters.
-r, --reverse	Sorts names in reverse order.
-s, --size	Displays file sizes in 1 KB blocks.
-t, --sort=time	Sorts directory contents by modification time, newest first.
-u, --time=atime, → --time=access, --time=use	Sorts names by last access time instead of the modification time.
-x, --format=across, → --format=horizontal	Displays names in columns, sorted horizontally.
-A, --almost-all	Lists all names except for “.” and “..”.
-B, --ignore-backups	Does not display names that end with “~”.
-C, --format=vertical	Displays names in columns, sorted vertically.
-G, --no-group	Does not display group information.
-L, --dereference	Lists names of symbolic links instead of the link contents.
-N, --literal	Does not quote names.
-Q, --quote-name	Quotes names in double quotes and nongraphic characters in C syntax.
-R, --recursive	Displays the contents of all directories recursively.
-S, --sort=size	Sorts names by file size, largest first.
-U, --sort=none	Does not sort names.
-X, --sort=extension	Sorts names alphabetically by file extension.
-1, --format=single-column	Lists one file per line.
-w, --width n	Sets display to n columns wide.
-T, --tabsize n	Sets tabs to n columns wide.
-I, --ignore pattern	Does not display names matching pattern.
--color, --colour, → --color=yes, --colour=yes	Displays the names in color depending on the type of file and terminal characteristics.
--color=tty, --colour=tty	Displays names in color only if standard output is a terminal.
--color=no, --colour=no	Disables color display of names.
--help	Displays help message.
--version	Displays version information.
lynx	Use to browse the Web.
-	Specifies to take arguments from standard input.
-anonymous	Specifes anonymous account.
-assume_charset=MIMEname	Specifies default character set.
-assume_local_charset= → MIMEname	Specifies character set for local files.
-assume_unrec_charset= → MIMEname	Specifies character set to use if remote character set is not recognizable.
-auth=ID:PASSWD	Specifies authorization ID and password for protected documents.
-base	Specifies HTML BASE tag to use when dumping source code.
-blink	Specifies high-intensity background colors for color mode if possible.
-book	Specifies bookmark page as initial file.
-buried_news	Specifies automatic conversion of embedded URLs to links in Netnews.
-cache=n	Specifies to cache n documents in memory.
-case	Specifies case-sensitive searching within pages.
-cfg=file	Specifies alternative lynx configuration file.
-child	Specifies no save to disk and quick exit with in first document.
-color	Specifies color mode, if possible.
-cookies	Toggles handling of cookies.
-core	Toggles core dumps on crashes.
-crawl –traversal	Specifies to output each browsed page to a file.
-dump	Specifies to dump formatted output of specified page to standard output.
-editor=editor	Enables editing with specified editor.
-emacskeys	Enables emacs-style key movement.
-enable_scrollback	Toggles scrollback when supported by communications programs.
-error_file=FILE	Specifies where to save error code.
-force_html	Specifies that the start document be considered HTML.
-force_secure	Toggles security flag for SSL cookies.
-from	Toggles use of From headers.
-ftp	Specifies no FTP access.
-get_data	Retrieves form data from standard input and dumps results.
-head	Requests MIME headers.
-help	Displays help message.
-hiddenlinks=→ [merge,listonly,ignore]	Specifies handling of hidden links.
-historical	Toggles use of > or --> as comment terminator.
-homepage=URL	Sets home page URL for session.
-image_links	Toggles display of links for all images.
-index=URL	Sets the default index file to the specified URL.
-ismap	Toggles presentation of links for client-side image maps.
-link=NUMBER	Specifies starting number for files crawled.
-localhost	Specifies only browsing on local host.
-locexec	Enables local program execution from local files.
-mime_header	Displays MIME header with document source.
-minimal	Toggles minimal or valid comment parsing.
-newschunksize=n	Specifies n articles in chunked news listings.
-newsmaxchunk=n	Specifies maximum number of news articles before chunking.
-nobrowse	Disables directory browsing.
-nocc	Disables prompts for user copies of sent mail.
-nocolor	Disables color mode.
-noexec	Disables local program execution.
-nofilereferer	Disables Referrer headers for file URLs.
-nolist	Disables link listings in formatted text output (dumps).
-nolog	Disables mailing error messages to document owners.
-nopause	Disables pauses on status messages.
-noprint	Disables printing.
-noredir	Disables automatic redirection.
-noreferer	Disables Referrer headers for all URLs.
-nosocks	Disables SOCKS proxy use.
-nostatus	Disables retrieval status messages.
-number_links	Numbers links.
-pauth=ID:PASSWD	Sets ID and password for a protected proxy server.
-popup	Toggles handling of single-choice SELECT options as pop-up windows or as lists of radio buttons.
-post_data	Sends form data from standard input with POST dump results.
-preparsed	Specifies that HTML source be preparsed and reformatted when viewed.
-print	Enables printing.
-pseudo_inlines	Toggles pseudo-ALT text for inline images with no ALT string.
-raw	Toggles default setting of 8-bit character translations or CJK mode for the initial character set.
-realm	Specifies access only to URLs in initial domain.
-reload	Specifies to empty proxy server cache and reload document.
-resubmit_posts	Toggles forced resubmissions of forms when the documents they returned are revisited.
-rlogin	Disables rlogin commands.
-selective	Restricts directory browsing to those specified with .www_browsable.
-show_cursor	Specifies cursor to be shown at start of current link.
-source	Sends output as HTML source to standard output.
-telnet	Disables Telnet commands.
-term=TERM	Specifies terminal type for lynx.
-tlog	Toggles lynx tracing log.
-trace	Enables WWW trace mode.
-traversal	Follows links from start file.
-underscore	Toggles use of underline in dumps.
-useragent=Name	Specifies alternative lynx User-Agent header name.
-validate	Accepts only HTTP URLs for validation.
-version	Displays version information.
-vikeys	Enables vi-like key movement.
-width=n	Specifies number of columns for dump formatting.
man	Use to display online manual pages.
-M path	Specifies the directories to search for man pages.
-P pager	Specifies which pager (more or less) to use.
-S section_list	Specifies list of manual sections to search.
-a	Specifies to display all matching man pages, not just the default first one.
-d	Specifies not to display man page; rather, display debugging information.
-f	Provides what is information.
-h	Prints help message.
-k	Searches for string in all man pages.
-m system	Specifies alternate man pages for system.
section, -s section	Specifies to display man page from the given section.
-w	Specifies not to display man pages; rather, print the path of the files.
-W	Specifies not to display man mages; rather, print the filenames without additional information.
mail	Use to send and receive mail.
-v	Specifies verbose mode and displays delivery details.
-i	Specifies to ignore interrupt signals.
-I	Specifies interactive mode even if input is not from a terminal.
-n	Disables mail.rc reading when starting.
-N	Disables initial display of message headers when reading mail.
-s subject	Specifies subject on command line.
-c addresses	Specifies addresses for carbon copies.
-b addresses	Specifies addresses for blind carbon copies.
-f file	Reads contents of file for processing and returns undeleted messages to this file.
mkdir	Use to make directories.
-m, --mode mode	Sets the mode of created directories as with chmod.
-p, --parents	Makes directories and any necessary parent directories.
--help	Displays help message.
--version	Displays version information.
more	Use to view files a screen at a time.
-num	Specifies number of lines onscreen.
-d	Specifies prompting and no bell on errors.
-l	Specifies not to pause after a in the file.
-f	Specifies to count logical lines rather than screen lines.
-p	Specifies not to scroll, but rather to clear and display new text.
-c	Specifies not to scroll, but rather to paint each screen from the top.
-s	Specifies to squeeze multiple blank lines together.
-u	Specifies to suppress underlining.
+/string	Specifies a string to find and start at for displaying the file.
+num	Specifies to start at line number num.
mutt	Use a small but very powerful text-based program for email.
-a file	Specifies to attach a file to your message.
-b address	Specifies a blind-carbon-copy (BCC) recipient.
-c address	Specifies a carbon-copy (CC) recipient.
-e command	Specifies a configuration command to be run after initialization files.
-f mailbox	Specifies which mailbox to load.
-F muttrc	Specifies an initialization file to read instead of ~/.muttrc.
-h	Specifies to display help information.
-H draft	Specifies a draft file to use for creating a message.
-i include	Specifies a file to include in a message.
-m type	Specifies a default mailbox type.
-n	Specifies to ignore the system configuration file.
-p	Specifies to resume a postponed message.
-R	Specifies to open a mailbox in read-only mode.
-s subject	Specifies the subject of the message.
-v	Specifies to display version information.
-x	Specifies to emulate mailx compose mode.
-y	Specifies to start with a listing of all mailboxes specified.
-z	Specifies not to start if there are no messages, when used with -f.
-Z	Specifies to open the first mailbox specified that contains new mail.
mv	Use to rename or move files.
-b, --backup	Specifies to make backups of files before removal.
-f, --force	Specifies to overwrite all existing destination files.
-i, --interactive	Requires prompting before overwriting.
-v, --verbose	Displays filenames before moving.
--help	Prints a help message.
--version	Prints version information.
-S, --suffix backup-suffix	Specifies suffix for backup files.
nice	Use to run a program with a different priority.
-n adjustment, -adjustment,--adjustment=adjustment	Adds adjustment number to initial priority.
--help	Displays help message.
--version	Displays version information.
passwd	Use to set a password for the system.
pico	Use for user-friendly text editing.
+n	Starts pico with the cursor located n lines into the file.
-d	Specifies that the key rubs out the character the cursor is on rather than the character to its left.
-e	Enables filename completion.
-f	Specifies to use function keys for commands.
-j	Specifies that goto commands to indicate directories are allowed.
-k	Specifies that “Cut Text” removes characters from the cursor position to the end of the line.
-nn	Enables mail notification every n seconds.
-o dir	Specifies operating directory.
-rn	Specifies column n for right margin of justify command.
-t	Sets tool mode for when pico is the default editor in other programs.
-v	Specifies view-only.
-w	Disables word wrap.
-x	Disables menu.
-z	Allows suspension of pico.
pine	Use to read news and email.
-d debug-level	Displays diagnostic information at levels from 0 (none) to 9 (complete).
-f folder	Specifies to open folder instead of in-box.
-F file	Opens specified file with pine.
-h	Displays brief help message.
-i	Specifies to start in folder index.
-I keystrokes	Specifies initial set of keystrokes to execute on startup.
-k	Specifies to use function keys for commands.
-n number	Specifies to start with given message number.
-o	Opens first folder as read-only.
-p config-file	Specifies configuration file to use instead of default personal configuration file.
-P config-file	Specifies configuration file to use instead of systemwide configuration file.
-r	Requires demo mode.
-z	Allows eventual suspension of pine process.
-conf	Outputs a new copy of systemwide configuration file.
-pinerc file	Outputs new pinerc configuration file.
-sort order	Specifies sort order in folders as arrival, subject, from, date, size, orderedsubj, thread, score, to, cc, or reverse.
ping	Use to see if a specific host is reachable.
-c count	Specifies number of responses to receive before stopping.
-d	Specifies SO_DEBUG option.
-f	Specifies flood ping (for system administrators only).
-i wait	Specifies how many seconds to wait between packets.
-l preload	Specifies initial flurry of packets before reverting to normal behavior; for system administrators only.
-n	Specifies not to look up domain names.
-p pattern	Specifies content for packets to diagnose data-dependent problems.
-q	Specifies quiet output with only initial and ending summary information displayed.
-r	Specifies to ignore routing and send directly to host on attached network.
-s packetsize	Specifies size of packet to send in bytes.
-v	Specifies verbose output and lists all received packets.
pgrep	Use to look up processes based on name or other characteristics.
-d string	Specifies the string used to delimit each process ID output.
-f	Specifies to match against full path.
-g pgrp,...	Specifies to match only processes under the specified process group IDs.
-G gid,...	Specifies to match only processes whose real group ID is listed.
-l	Specifies to list the process name as well as the process ID.
-n	Specifies to list only the newest matching process.
-P ppid,...	Specifies to match only processes whose parent process ID is listed.
-s sid,...	Specifies to match only processes whose process session ID is listed.
-t term,...	Specifies to match only processes whose controlling terminal is listed.
-u euid,...	Specifies to match only processes whose effective user ID is listed.
-U uid,...	Specifies to match only processes whose real user ID is listed.
-v	Specifies to match the opposite of the characteristics given.
-x	Specifies to match only exactly.
pkill	Use to send a kill signal to processes based on name or other characteristics.
-f	Specifies to match against full path.
-g pgrp,...	Specifies to match only processes under the specified process group IDs.
-G gid,...	Specifies to match only processes whose real group ID is listed.
-n	Specifies to list only the newest matching process.
-P ppid,...	Specifies to match only processes whose parent process ID is listed.
-s sid,...	Specifies to match only processes whose process session ID is listed.
-t term,...	Specifies to match only processes whose controlling terminal is listed.
-u euid,...	Specifies to match only processes whose effective user ID is listed.
-U uid,...	Specifies to match only processes whose real user ID is listed.
-v	Specifies to match the opposite of the characteristics given.
-x	Specifies to match only exactly.
-signal	Specifies the signal (numeric or by name) to send to each matched process.
procmail	Use to process incoming email.
-v	Specifies to display version information.
-p	Specifies to preserve existing environment.
-t	Specifies to retry failed deliveries later.
-f name	Specifies to regenerate the From line that separates messages with name.
-o	Specifies to override fake From lines.
-Y	Specifies to ignore any Content-Length: fields.
-a argument	Specifies arguments to pass to procmail.
-d recipient ...	Specifies delivery mode.
-m	Specifies that procmail should act as a general-purpose mail filter.
ps	Use to report process status (note that ps arguments work with or without a -, and warn you not to use - in the future).
-l	Specifies long format.
-j	Specifies jobs format.
-s	Specifies signal format.
-v	Specifies vm (virtual memory) format.
-m	Displays thread information.
-H	Specifies “forest” tree format.
-f	Show full listing.
-a	Displays processes of other users on the same terminal.
-x	Displays processes without controlling terminal (daemons).
-S	Displays add child CPU time and page faults.
-w	Specifies wide output and does not truncate command lines.
-h	Disables header display.
-r	Shows running processes only.
-n	Specifies numeric output for user and wchan fields.
-txx	Specifies only processes with controlling tty xx.
-pids	Lists only specified processes.
--help	Displays help message.
--version	Displays version information.
pr	Use to convert and reformat files for printing or display.
-n, --columns=n	Specifies to create n columns across the page.
-c, --show-control-chars	Specifies to use hat notation (^G) and octal backslash notation.
-d, --double-space	Specifies to double space the output.
-D, --date-format=FORMAT	Specifies to use FORMAT for the header date.
-F, -f, --form-feed	Specifies to use form feeds instead of newlines to separate pages.
-h header, --header=header	Specifies to use a centered header instead of filename in page header.
-t, --omit-header	Specifies to omit page headers and footers.
-T, --omit-pagination	Specifies to omit page headers, footers, and all pagination.
-v, --show-nonprinting	Specifies to use octal backslash notation to display nonprinting characters.
-W w, --page-width=w	Specifies that page width be w (72 default) characters.
--help	Specifies to display help message.
--version	Specifies to display version information.
pwd	Use to display name of current working directory.
--help	Displays help message.
--version	Displays version information.
quota	Use to display disk usage and limits.
-g	Displays group quotas for the executing user’s group.
-v	Displays quotas on file systems where no storage is allocated.
-q	Displays only information for file systems over quota.
renice	Use to change the priority (niceness) of jobs.
-g	Specifies to force parameters to be interpreted as process group IDs.
-u	Specifies to force parameters to be interpreted as user names.
-p	Specifies to require parameters to be process IDs.
rm	Use to remove files.
-f, --force	Specifies to overwrite all existing destination files.
-i, --interactive	Requires prompting before overwriting.
-R, --recursive	Specifies to copy directories recursively.
-v, --verbose	Displays filenames before moving.
--help	Displays a help message.
--version	Displays version information.
reset	Use to reset a terminal session to normal behavior.
-q	Specifies to display the terminal type only.
-e a	Specifies to set the erase character to the given character.
-I	Specifies not to send initialization strings to the terminal.
-Q	Specifies not to display values for erase, interrupt, and line kill characters.
-V	Specifies to display the version number.
-i a	Specifies to set the interrupt character to the given character.
-k a	Specifies to set the line kill character to the given character.
-m	Specifies to map a port type to a terminal type.
-r	Specifies to display the terminal type to standard error.
-s	Specifies to display the initialization commands.
rmdir	Use to remove empty directories.
-p, --parents	Specifies to remove any parent directories listed, if they are empty after the specified files are removed.
--help	Displays a help message.
--version	Displays version information.
rsync	Use to copy files and synchronize directories.
-v, --verbose	Specifies to increase verbosity.
-q, --quiet	Specifies to decrease verbosity.
-c, --checksum	Specifies to calculate a checksum for files, not just check dates.
-a, --archive	Specifies to use archive mode.
-r, --recursive	Specifies to recursively copy.
-R, --relative	Specifies to use relative path names.
-b, --backup	Specifies to make backups with the default ~ suffix.
--backup-dir	Specifies to use this backup directory.
--suffix=string	Specifies to change backup suffix to string.
-u, --update	Specifies to update only and not overwrite newer files.
-l, --links	Specifies to copy symlinks as symlinks.
-L, --copy-links	Specifies to copy the associated file for symlinks.
--copy-unsafe-links	Specifies to copy links outside the source directory tree.
--safe-links	Specifies to ignore links outside the destination directory tree.
-H, --hard-links	Specifies to preserve hard links.
-p, --perms	Specifies to preserve permissions.
-o, --owner	Specifies to preserve owner, for use by root only.
-g, --group	Specifies to preserve group.
-D, --devices	Specifies to preserve devices, for use by root only.
-t, --times	Specifies to preserve times.
-S, --sparse	Specifies to handle sparse files efficiently.
-n, --dry-run	Specifies to show what would have been transferred, but not actually transfer.
-W, --whole-file	Specifies to copy whole files without making incremental checks.
--no-whole-file	Specifies not to copy whole files without checking.
-x, --one-file-system	Specifies not to cross file system boundaries.
-B, --block-size=SIZE	Specifies the checksum block size (default 700).
-e, --rsh=COMMAND	Specifies the rsh replacement command (probably ssh).
--rsync-path=PATH	Specifies the path to rsync on the remote machine.
-C, --cvs-exclude	Specifies to autoignore files in the same way CVS does.
--existing	Specifies to update only files that already exist.
--ignore-existing	Specifies to ignore files that already exist on the receiving side.
--delete	Specifies to delete files that don’t exist on the sending side.
--delete-excluded	Specifies to also delete excluded files on the receiving side.
--delete-after	Specifies to delete after transferring, not before.
--ignore-errors	Specifies to delete even if there are I/O errors.
--max-delete=NUM	Specifies not to delete more than NUM files.
--partial	Specifies to keep partially transferred files.
--force	Specifies to force deletion of directories even if not empty.
--numeric-ids	Specifies to set permissions with numeric ids on target.
--timeout=n	Specifies to set I/O timeout in seconds.
-I, --ignore-times	Specifies to copy even files that match in length and time.
--size-only	Specifies to copy files only if file sizes differ.
--modify-window=n	Specifies range of time (n seconds) to consider equivalent.
-T --temp-dir=path	Specifies to create temporary files in directory path.
--compare-dest=DIR	Specifies to compare destination files relative to path.
-z, --compress	Specifies to compress files when transferring.
--exclude=string	Specifies to exclude files matching string.
--exclude-from=file	Specifies to exclude patterns listed in file.
--include=string	Specifies to include files matching string.
--include-from=file	Specifies to include patterns listed in file.
--version	Specifies to display version number.
--daemon	Specifies to run as an rsync daemon.
--no-detach	Specifies not to detach from the parent.
--address=ADDRESS	Specifies to bind to the specified address.
--config=file	Specifies an alternate rsyncd.conf file.
--port=PORT	Specifies an alternate rsyncd port number.
--blocking-io	Specifies to use blocking I/O for the remote shell.
--no-blocking-io	Specifies to turn off --blocking-io.
--stats	Specifies to show some file transfer statistics.
--progress	Specifies to show progress during transfer.
--log-format=format	Specifies to log file transfers using specified format.
--password-file=file	Specifies to get password from file.
--bwlimit=n	Specifies to limit I/O bandwidth to n KBps.
--read-batch=string	Specifies to read batch fileset starting with string.
--write-batch=string	Specifies to write batch fileset starting with string.
-h, --help	Specifies to display help information.
sed	Use for processing and editing files in batch mode.
-e	Specifies edit commands to follow as the next argument.
-f	Specifies edit commands to be taken from named file or files.
-n	Suppresses default output.
set	Use to set or view the values of variables.
setenv	Use to change or view the value of an environment variable (csh).
screen	Use to manage multiple virtual screens in a physical window.
-a	Specifies to include all capabilities in each window.
-A	Specifies to adapt the sizes of all windows to the size of the current terminal.
-c file	Specifies to override the default configuration file (~/.screenrc) with file.
-d,-D	Specifies to detach another running screen from the controlling terminal.
-d -r	Specifies to reattach a session, after detaching it if necessary.
-d -R	Specifies to reattach a session, after detaching or creating it first if necessary.
-d -RR	Specifies to reattach a session, after detaching or creating it if necessary, and to use the first session if multiple sessions are available.
-D -r	Specifies to reattach a session, after detaching and logging out remotely if necessary.
-D -R	Specifies to attach immediately, after notifying other users.
-D -RR	Specifies to attach immediately, after doing anything necessary to other sessions.
-e xy	Specifies the command character (default is Aa), specified as ^Aa.
-f, -fn, -fa	Specifies flow-control settings to off, on, or automatic.
-h n	Specifies the size of the history as n lines.
-l, -ln	Specifies to turn login mode on or off.
-ls, -list	Specifies to display list of existing screen sessions.
-m	Specifies to force creation of a new session.
-d -m	Specifies to start screen in detached mode.
-D -m	Specifies to start screen in detached mode, in existing process.
-q	Specifies to suppress display error messages and exit codes.
-r	Specifies to resume a detached screen session.
-R	Specifies to attempt to resume the first available detached screen session it finds.
-s string	Specifies the default shell as string.
-S name	Specifies to use name as the name for the new session.
-t name	Specifies the title for the default shell or specified program.
-v	Specifies to display the version number.
-wipe	Specifies to remove destroyed sessions.
-x	Specifies to attach to a session in multidisplay mode.
-X	Specifies to send the specified command to a running screen session.
ssh	Use to securely log in to and run commands on a remote system.
-a	Specifies not to forward the authentication agent connection.
-A	Specifies to forward the authentication agent connection.
-b bind_address	Specifies the interface to transmit from if multiple interfaces are available.
-c blowfish|3des|des	Specifies the encrpytion method to use.
-e ch|^ch|none	Specifies the escape character for sessions with a pty (default: ~).
-f	Specifies for ssh to go to the background before the command runs.
-g	Specifies that remote hosts can connect to local forwarded ports.
-i identity_file	Specifies the file from which to read the identify key.
-l login_name	Specifies the user name to log in as on the remote machine.
-n	Specifies to ignore standard input.
-N	Specifies not to execute a remote command.
-o option	Specifies to give options as presented in configuration file.
-p port	Specifies the port to connect to on the remote host.
-P	Specifies a nonprivileged port (<1024) for outgoing connections.
-q	Specifies that warning and diagnostic messages should be suppressed.
-s	Specifies to request invocation of a subsystem on the remote system.
-t	Specifies to allocate a pseudo-tty.
-T	Specifies not to allocate a pseudo-tty.
-v	Specifies to provide verbose output.
-x	Specifies to disable X11 forwarding.
-X	Specifies to enable X11 forwarding.
-C	Specifies to compress all data for transmission.
-F configfile	Specifies an alternative configuration file.
-L port:host:hostport	Specifies port forwarding from local to remote sides.
-R port:host:hostport	Specifies port forwarding from remote to local sides.
-D port	Specifies dynamic port forwarding from local to remote sides.
-1	Specifies to use only protocol version 1.
-2	Specifies to use only protocol version 2.
-4	Specifies to use only IPv4 addresses.
-6	Specifies to use only IPv6 addresses.
split	Use to split files into smaller parts.
-b, --bytes=n	Specifies to put n bytes in each output file (use k for kilobytes, m for megabytes).
-C, --line-bytes=n	Specifies to put no more than n bytes of lines in each output file.
-l, --lines=n	Specifies to put n lines into each output file.
--verbose	Specifies to provide verbose output.
--help	Specifies to display help information.
--version	Specifies to display version information.
sort	Use to sort text files by line.
-c	Checks to see if file is already sorted.
-m	Merges sorted files together.
-b	Ignores extra spaces at the beginning of each line.
-d	Sorts by ignoring everything but letters, digits, and blanks.
-f	Sorts without case sensitivity.
-M	Sorts by month, recognizing three-character month abbreviations.
-n	Sorts numerically.
-r	Reverses result order.
-o output-file	Sends output to specified file instead of standard output.
-t separator	Uses indicated character as field separator.
-u	Displays only one of the matching lines.
--help	Displays help information.
--version	Displays version information.
su otherid	Use to substitute otherid for current userid.
-c command, --command=command	Runs specified command as other user.
--help	Displays help information.
-, -l, --login	Specifies to start as login shell.
-m, -p, --preserve-environment	Specifies not to change environment variables from current settings.
-s, --shell shell	Uses the specified shell instead of the default.
--version	Displays program version.
sudo	Use to execute a command as another user.
-V	Specifies to display the version number.
-l	Specifies to list the available and forbidden commands for the issuing user.
-L	Specifies to list configurable default parameters.
-h	Specifies to display a help message.
-v	Specifies to update the timestamp and extend the timeout.
-k	Specifies to set the timeout to a past time, forcing revalidation.
-K	Specifies to remove the timestamp for a current user.
-b	Specifies to run the specified command in the background.
-p	Specifies to replace the default password prompt with a custom prompt.
-u user	Specifies user, under whose id the command will run.
-s	Specifies to use the specified (default) shell.
-H	Specifies to change the $HOME environment variable to the target user.
-P	Specifies to preserve the user’s group ID when running the command.
-S	Specifies to read password from standard input.
--	Specifies to stop processing command-line options.
-	Specifies to force a login shell.
tail	Use to output the last part of a file.
-c --bytes n[b,k,m]	Displays last n bytes of file, in b (512-byte), k (1 KB), or m (1 MB) blocks.
-f, --follow	Specifies to keep running and trying to read more from end of file.
-l, -n N,--lines N	Displays last N lines of file.
-q, --quiet, --silent	Specifies not to display filenames.
-v, --verbose	Specifies to always display filenames.
--help	Displays help message.
--version	Displays version information.
talk	Use to talk to another user.
tar	Use to create tar archives.
-A, --catenate, --concatenate	Specifies to append tar files to an archive.
-c, --create	Creates a new archive.
-d, --diff, --compare	Identifies differences between archive and file system.
--delete	Removes files from the archive.
-r, --append	Appends files to the archive.
-t, --list	Lists contents of the archive.
-u, --update	Updates archive with newer files.
-x, --extract, --get	Extracts files from archives.
--atime-preserve	Specifies not to change access times.
-b, --block-size n	Specifies block size of nx512 bytes.
-C, --directory DIR	Changes to specified directory.
--checkpoint	Displays directory names while processing.
-f, --file	Uses specified file or device.
--force-local	Forces local archive file regardless of filename.
-h, --dereference	Processes linked files, not symbolic links.
-i, --ignore-zeros	Specifies to ignore zeros in archives (and not to interpret as EOF).
-k, --keep-old-files	Specifies that old files should be retained, not overwritten.
-K, --starting-file file	Starts at file file in the archive.
-l, --one-file-system	Specifies to remain in current file system.
-m, --modification-time	Specifies not to extract the file modification time.
-M, --multi-volume	Specifies to process as multivolume archive.
-N, --after-date date,→ --newer date	Stores files newer than date.
-o, --old-archive,→ --portability	Specifies old archive format.
-O, --to-stdout	Specifies to extract files to standard output.
-p, --same-permissions,→ --preserve-permissions	Specifies to extract all permissions data.
-P, --absolute-paths	Specifies to maintain absolute paths.
--remove-files	Specifies to remove files that have been added to archive.
-s, --same-order,→ --preserve-order	Specifies list of filenames to match archive.
--same-owner	Specifies to extract files with same ownership.
-T, --files-from file	Retrieves names of files to extract or create from file file.
--totals	Displays total bytes of created files.
-v, --verbose	Displays verbose information about processed files.
-V, --label name	Creates archive with volume name of name.
--version	Displays version information.
-w, --interactive,→ --confirmation	Requires confirmation for actions.
-W, --verify	Verifies information in archive after creating archive.
--exclude file	Specifies to exclude file from archive.
-X, --exclude-from file	Specifies to exclude files listed in file from archive.
-Z, --compress,→ --uncompress	Specifies to compress or uncompress the archive.
-z, --gzip, --ungzip	Specifies to process the archive with gzip.
--use-compress-program→ program	Specifies name of compression program as program.
tee	Use to read from standard input and write to standard output and files.
-a, --append	Appends to specified files instead of overwriting.
--help	Prints help information.
-i, --ignore-interrupts	Specifies to ignore interrupt signals.
--version	Prints version information.
telnet	Use to connect to and use remote computers.
-8	Specifies 8-bit operation, which is not the telnet default.
-E	Disables the escape character.
-L	Specifies 8-bit operation on output.
-a	Attempts automatic log in with the current user name.
-d	Enables debugging output.
-r	Specifies rlogin emulation.
-e character	Specifies the escape character to control command-mode access.
-l user	Specifies the user for remote log in.
-n tracefile	Starts tracing connection to tracefile.
tidy	Use to validate, correct, and clean up HTML files.
-config file	Specifies to set options from file.
-indent, -i	Specifies to indent contents of elements.
-omit, -o	Specifies to omit optional endtags.
-wrap n	Specifies to wrap output at column n.
-upper, -u	Specifies to output tags in uppercase.
-clean, -c	Specifies to replace formatting tags with CSS-style properties.
-raw	Specifies to output characters with values higher than 127 unchanged.
-ascii	Specifies to use Latin-1 (ISO 8859-1) character set for input, and US ASCII character set for output.
-latin1	Specifies to use Latin-1 (ISO 8859-1) character set for both input and output.
-iso2022	Specifies to use ISO 2022 character set for both input and output.
-utf8	Specifies to use UTF-8 character set for both input and output.
-mac	Specifies to use MacRoman character set for input.
-numeric, -n	Specifies to output numeric rather than named entities.
-modify, -m	Specifies to modify original files in place.
-errors, -e	Specifies to only show errors without modifying the original file.
-quiet, -q	Specifies to suppress extra output.
-f file	Specifies to write errors to file.
-xml	Specifies that input is well-formed XML.
-asxml	Specifies to convert HTML to well-formed XML.
-slides	Specifies to break file into slides based on <H2> elements.
-help, -h	Specifies to display a help message.
--configuration-option→ value	Specifies to set any configurable option to value.
time	Use to time a job.
tin	Use to read Usenet news.
-c	Creates or updates index for listed groups, marking all as read.
-f file	Specifies file to use for newsrc data.
-h	Displays help information.
-H	Displays introduction to tin.
-I dir	Specifies directory to hold newsgroup index files.
-m dir	Specifies mailbox directory to use.
-M user	Mails unread articles to user.
-n	Specifies to load only active, subscribed groups.
-q	Specifies startup without checking for new newsgroups.
-P	Purges all articles that do not exist. Time-consuming, particularly on a slow connection.
-r	Specifies remote news reading from nntpserver.
-s dir	Saves articles to directory specified.
-S	Saves unread articles for later reading with -R option.
-u	Creates and updates index files for all groups.
-U	Starts tin in background to update index files while reading news.
-v	Specifies verbose mode for some commands.
-w	Allows quick posting.
-z	Specifies to start tin only with new or unread news.
-Z	Checks for new or unread news.
touch	Use to change file times and create empty files.
-a, --time=atime, → --time=access, → --time=use	Changes access time only.
-c, --no-create	Specifies not to create files that do not already exist.
-d, --date time	Updates files with given (not current) time.
-m, --time=mtime, → --time=modify	Changes modification time only.
-r, --reference file	Updates files with time of reference file.
-t [[CC]YY]MMDDhhmm[.ss]	Specifies time argument for setting time.
--help	Displays help message.
--version	Displays version information.
tr	Use to translate or delete characters.
--help	Specifies to display help message.
--version	Specifies to display version information.
traceroute	Use to identify the route packets take to a network host.
-f	Specifies initial time-to-live used in the first probe.
-F	Specifies “don’t fragment” setting for probes.
-d	Enables socket-level debugging.
-g	Specifies a source route gateway.
-i	Specifies a network interface to use for probes.
-I	Specifies ICMP ECHO instead of UDP datagrams.
-m	Specifies maximum number of hops to use.
-n	Specifies not to look up domain names for addresses.
-p	Sets base UDP port number for probes.
-r	Specifies to ignore routing and send directly to host on attached network.
-s	Specifies IP address as source for probe.
-v	Specifies verbose output and lists all received packets.
-w	Specifies the number of seconds to wait for a response to a probe.
umask	Use to set the file creation mask.
unalias	Use to remove aliases from the list.
-a	Removes all alias definitions.
uname	Use to display system information.
-m, --machine	Displays the machine or hardware type.
-n, --nodename	Displays the node or host name.
-r, --release	Displays the operating system release number.
-s, --sysname	Displays the operating system name.
-v	Displays the operating system version.
-a, --all	Displays all the above information.
--help	Displays help information.
--version	Displays version information.
uniq	Use to remove duplicate lines from a sorted list.
-u, --unique	Outputs only unique lines.
-d, --repeated	Outputs only duplicate lines.
-c, --count	Outputs number of occurences of each line followed by the text of each line.
-number, -f, → --skip-fields=number	Specifies number of fields to ignore before checking for uniqueness.
+number, -s, → --skip-chars=number	Specifies number of characters to skip before checking for uniqueness.
-w, --check-chars=number	Specifies number of characters to compare.
--help	Prints help information.
--version	Prints version information.
units	Use to convert from one kind of unit to another.
-c, --check	Specifies to check that the units data file is valid.
--check-verbose	Specifies to check that the units data file is valid, with verbose output.
-o format, --output-format → format	Specifies the format for numeric output (in printf syntax).
-f filename, --file → filename	Specifies to use filename as the units data file.
-h, --help	Specifies to display a help message.
-q, --quiet, --silent	Specifies quiet output and suppression of prompts.
-s, --strict	Specifies not to convert to reciprocal units.
-v, --verbose	Specifies more verbose output.
-V, --version	Specifies to display version number.
unzip	Use to manipulate and extract compressed files in a zip file.
-f	Specifies to extract only files newer than those on disk.
-l	Lists archive files in short format.
-p	Extracts files to standard output.
-t	Tests archive files for accuracy and completeness.
-T	Sets the timestamp to the same as the newest file in the archive.
-u	Updates existing files from the archive and creates new files as needed.
-v	Displays verbose or diagnostic version information.
-z	Displays archive comments.
-j	Junks paths and puts all files in the current directory.
-n	Specifies never to overwrite existing files.
-o	Overwrites existing files without prompting.
-P password	Requires password to decrypt zip file entries.
-q	Performs operations quietly, without displaying most status information.
-qq	Performs operations even more quietly.
uudecode	Use to decode a file created by uuencode.
-o file	Directs output to file.
uuencode	Use to encode a binary file.
-m	Specifies MIME (Base 64) encoding.
vacation	Use to reply to mail automatically.
-I	Initializes .vacation.db file and starts vacation.
-a alias	Specifies alias for vacation user, so that mail sent to that alias generates a reply.
-j	Specifies to always reply, regardless of To: or CC: addressing.
-tn	Specifies the number of days between repeat replies to the same sender.
-r	Specifies to use the “Reply-To:” header if available.
-?	Displays a short help message.
vi	Use for powerful text editing.
-s	Specifies no interactive feedback.
-l	Specifies LISP program editing setup.
-L	Lists names of files saved after crashes.
-R	Forces read-only mode.
-r filename	Recovers filename edit file saved after a crash.
-t tag	Starts editor with cursor at tag position.
-V	Specifies verbose output with input echoed to standard error.
-x	Specifies encryption option like that of ex and prompts for a key.
-wn	Specifies default window size.
-x	Specifies encryption option like that of ex and prompts for a key, assuming all text is encrypted.
+command, -c command	Starts editor and executes specified command.
w	Use to show who is logged on and what they are doing.
-h	Disables header.
-n	Ignores user name for current process and CPU times.
-s	Specifies short format, omitting log in, JCPU, and PCPU times.
-f	Toggles display of remote host name.
-V	Displays version information.
watch	Use to execute a program repeatedly with full-screen output.
-h, --help	Specifies to display a help message.
-v, --version	Specifies to display version number.
-n=n, --interval	Specifies to override the default 2-second interval with n.
-d, --differences	Specifies to display differences between successive updates.
--cumulative	Specifies to keep all changes highlighted.
wc	Use to count the number of bytes, words, and lines in a file.
-c, --bytes, --chars	Displays only byte counts.
-w, --words	Displays only word counts.
-l, --lines	Displays only newline counts.
--help	Displays help message.
--version	Displays version information.
wget	Use to download files or entire Web sites.
-V, --version	Specifies to display the version number.
-h, --help	Specifies to display a help message.
-b, --background	Specifies to start as a background process.
-e command, --execute → command	Specifies to execute command at end of startup process.
-o logfile, → --output-file=logfile	Specifies to log all messages to the specified file.
-a logfile, → --append-output=logfile	Specifies to append all messages to the specified file.
-d, --debug,	Specifies to display debugging information.
-q, --quiet	Specifies to suppress output.
-v, --verbose	Specifies to provide verbose output (the default setting).
-nv, --non-verbose	Specifies to provide nonverbose, nonquiet output.
-i file, → --input-file=file	Specifies to read URLs from the file given.
-F --force-html	Specifies to force input to be treated as an HTML file.
-B URL, --base=URL	Specifies to prepend URL to relative links in specified file.
-t n, --tries=n	Specifies number of retries. Use 0 for infinite.
-O file, → --output-document=file	Specifies to concatenate all documents as file or - for standard output.
-nc --no-clobber	Specifies to not destroy a file of the same name as the file being downloaded.
-c --continue	Specifies to continue getting a partially downloaded file.
--progress=type	Specifies type of the progress indicator as “dot” and “bar”.
-N --timestamping	Specifies to enable time stamps.
-S --server-response	Specifies to print the headers and responses sent by servers.
--spider	Specifies to verify pages but not download them.
-T seconds --timeout=seconds	Specifies length of the read timeout in seconds.
--limit-rate=n	Specifies to limit the download speed to n bytes (or kilobytes with k, or megabytes with m) per second.
-w n --wait=n	Specifies to wait the specified number (n) of seconds between retrievals.
--waitretry=n	Specifies interval to wait before retrying failed downloads.
--random-wait	Specifies to wait random intervals between requests.
-Y on/off, --proxy=on/off	Specifies to turn proxy support on or off.
-Q quota --quota=quota	Specifies the download quota (in b, k, or m) for automatic retrieval.
-nd --no-directories	Specifies not to create a hierarchy of directories on recursive retrieval.
-x --force-directories	Specifies always to create a hierarchy of directories on recursive retrieval.
-nH --no-host-directories	Specifies not to create host name-prefixed directories.
--cut-dirs=number	Specifies to ignore (flatten) specific numbers of directory levels.
-P prefix → --directory-prefix=prefix	Specifies directory prefix to use.
-E --html-extension	Specifies to append .html to filenames.
--http-user=user → --http-passwd=password	Specifies the user name user and password password for an HTTP server.
-C on/off --cache=on/off	Specifies to avoid or use server-side caching.
--cookies=on/off	Specifies to use or disable cookies.
--load-cookies file	Specifies to load cookies from file before the first retrieval.
--save-cookies file	Specifies to save cookies to file at the end of the session.
--ignore-length	Specifies to ignore “Content-Length” headers.
--header=additional-header	Specifies to define an additional-header to be passed to the HTTP servers.
--proxy-user=user → proxy-passwd=password	Specifies the user name user and password password for authentication on a proxy server.
--referer=url	Specifies to include “Referer: url” header in HTTP request.
-s --save-headers	Specifies to save the headers sent by the HTTP server to the file.
-U agent-string → --user-agent=agent-string	Specifies agent-string to send to the HTTP server.
-nr --dont-remove-listing	Specifies not to remove the temporary listing files generated by FTP retrievals.
-g on/off --glob=on/off	Specifies to turn FTP globbing (wildcard use) on or off.
--passive-ftp	Specifies to use the passive FTP retrieval method for use behind firewalls.
--retr-symlinks	Specifies to retrieve files pointed to by symbolic links.
-r --recursive	Specifies to turn on recursive retrieving.
-l depth --level=depth	Specifies the maximum depth for recursive retrieval.
--delete-after	Specifies to delete files downloaded, as soon as they’re retrieved.
-k --convert-links	Specifies to convert the links in the document for local viewing.
-K --backup-converted	Specifies to back up the original version with a .orig suffix.
-m --mirror	Specifies to turn on options suitable for mirroring.
-p --page-requisites	Specifies to download all required files to display a page.
-A acclist --accept acclist→ -R rejlist --reject rejlist	Specifies lists of filename patterns to accept or reject.
-D domain-list → --domains=domain-list	Specifies domains to be followed.
--exclude-domains domain-list	Specifies the domains that are not to be followed.
--follow-ftp	Specifies to follow FTP links from HTML documents.
--follow-tags=list	Specifies to use list for tags that indicate links.
-G list --ignore-tags=list	Specifies to ignore listed tags for indication of links.
-H --span-hosts	Specifies to recursively retrieve from multiple hosts.
-L --relative	Specifies to follow relative links only.
-I list → --include-directories=list	Specifies a list (with wildcards) of directories to follow when downloading.
-X list → --exclude-directories=list	Specifies a list (with wildcards) of directories to exclude when downloading.
-np --no-parent	Specifies not to download from the parent directory.
whereis	Use to find information about the specified file.
-b	Specifies to search only for binary files.
-m	Specifies to search only for man pages.
-s	Specifies to search only for source files.
-u	Specifies to search for unusual entries, which are files with fewer than one binary, man, and source entry.
-B	Specifies to change or limit where whereis searches for binaries.
-M	Specifies to change or limit where whereis searches for man pages.
-S	Specifies to change or limit where whereis searches for source files.
-f	Specifies to end the directory list and start the filename list for use with the -B, -M, or -S options.
who	Use to display information about who is logged onto the system.
-m	Specifies “me”, as in “who am I?”.
-q, --count	Displays login names and total number of logged on users.
-i, -u, --idle	Displays idle time.
-H, --heading	Displays column headings.
-w, -T, --mesg, --writable	Displays user message status.
--help	Displays a help message.
--version	Displays version information.
write	Use to send a message to another user.
ydecode	Use to decode yencoded files.
yencode	Use to encode files with the yEnc algorithm.
zsh	Use the flexible, powerful Z shell.
-c	Specifies to take the first argument as a command to execute.
-i	Specifies to force an interactive shell.
-s	Specifies to force shell to read commands on standard input.
--version	Specifies to print the version number.
--help	Specifies to print help information.
zip	Use to create a zip-format file archive.
-A	Accommodates a self-extracting executable archive.
-b path	Specifies a path for the temporary files.
-c	Provides one-line comments for each file in the archive.
-d	Deletes entries from an archive.
-D	Specifies not to create entries in the zip archive for directories.
-e	Encrypts the contents of the zip archive using a password.
-f	Freshens an existing entry in the archive if the new file has been modified more recently than the version in the zip archive.
-F	Fixes the zip archive.
-g	Appends to the specified archive.
-h	Displays help information.
-i files	Includes only specified files.
-j	Junks path name and stores only filename.
-J	Junks prepended data (for self-extracting archives) from the archive.
-l	Translates Unix text files to MS-DOS text files.
-ll	Translates MS-DOS text files to Unix text files.
-L	Displays the zip license.
-m	Moves specified files into the archive and deletes originals.
-n suffixes	Specifies not to compress files with the given suffixes.
-o	Sets the modification time of the zip archive to that of oldest of the files in the archive.
-q	Specifies quiet mode to eliminate messages and prompts.
-r	Includes files and directories recursively.
-t mmddyyyy	Ignores files modified before the given date.
-T	Tests the new archive and reverts to the old archive if errors are found.
-u	Updates an existing entry in the archive only if the existing file has been changed more recently than the copy in the archive.
-v	Specifies verbose mode to print diagnostic and version information.
-x files	Excludes the specified files.
-z	Requires a multiline comment for the entire archive.
-@	Gets a list of input files from standard input.