External diff3
Subversion calls external merge programs with parameters suitable for the GNU diff3 utility, expecting that the external program will return with a successful error code and that the full file contents that result from the completed merge operation are printed on the standard output stream (so that Subversion can redirect them into the appropriate version-controlled file). For most alternative merge programs, only the 9th, 10th, and 11th arguments, the paths of the files which represent the “mine,” “older,” and “yours” inputs, respectively, are of interest. Note that because Subversion depends on the output of your merge program, your wrapper script must not exit before that output has been delivered to Subversion. When it finally does exit, it should return an error code of 0 if the merge was successful or 1 if unresolved conflicts remain in the output—any other error code is considered a fatal error.
Examples 7-4 and 7-5 are templates for external merge tool wrappers in the Python and Windows batch scripting languages, respectively.
#!/usr/bin/env python import sys import os # Configure your favorite diff program here. DIFF3 = "/usr/local/bin/my-merge-tool" # Subversion provides the paths we need as the last three parameters. MINE = sys.argv[-3] OLDER = sys.argv[-2] YOURS = sys.argv[-1] # Call the merge command (change the following line to make sense for # your merge program). cmd = [DIFF3, '--older', OLDER, '--mine', MINE, '--yours', YOURS] os.execv(cmd[0], cmd) # After performing the merge, this script needs to print the contents # of the merged file to stdout. Do that in whatever way you see fit. # Return an errorcode of 0 on successful merge, 1 if unresolved conflicts # remain in the result. Any other errorcode will be treated as fatal.
@ECHO OFF REM Configure your favorite diff3/merge program here. SET DIFF3="C:Program FilesFunky StuffMy Merge Tool.exe" REM Subversion provides the paths we need as the last three parameters. REM These are parameters 9, 10, and 11. But we have access to only REM nine parameters at a time, so we shift our nine-parameter window REM twice to let us get to what we need. SHIFT SHIFT SET MINE=%7 SET OLDER=%8 SET YOURS=%9 REM Call the merge command (change the following line to make sense for REM your merge program). %DIFF3% --older %OLDER% --mine %MINE% --yours %YOURS% REM After performing the merge, this script needs to print the contents REM of the merged file to stdout. Do that in whatever way you see fit. REM Return an errorcode of 0 on successful merge, 1 if unresolved conflicts REM remain in the result. Any other errorcode will be treated as fatal.