A third-party merge program to be used by p4 resolve's merge option.

The program represented by the program name stored in this variable is used only by p4 resolve's merge option. When p4 resolve calls this program, it passes four arguments, representing (in order) base, theirs, and yours, with the fourth argument holding the resulting merge file.

If the program you use takes its arguments in a different order, set P4MERGE to a shell script or batch file that reorders the arguments and calls the proper merge program with the arguments in the correct order.

If you are running under Windows, you must call a batch file, even if your third-party merge program already accepts arguments in the order provided by Perforce. This is due to a limitation within Windows. For instance, if you want to use a program called MERGE.EXE under Windows, your batch file might look something like this:

SET base=%1
SET theirs=%2
SET yours=%3
SET merge=%4
C:\FULL\PATH\TO\MERGE.EXE %base% %theirs% %yours% %merge%