p4 diff


Compare a client workspace file to a revision in the depot.


p4 [g-opts] diff [-doptions] [-f -t -Od] [-m max] [-soptions] [file[rev] …]


p4 diff runs a diff program on your workstation that compares files in your workspace to revisions in the depot.

This command takes a file argument, which can contain a revision specifier. If a revision specifier is included, the file in the client workspace is diffed against the specified revision. If a revision specifier is not included, the client workspace file is compared against the revision currently being edited (usually the head revision). In either case, the client file must be open for edit, or the comparison must be against a revision other than the one to which the client file was last synced.

If the file argument includes wildcards, all open files that match the file pattern are diffed. If no file argument is provided, all open files are diffed against their depot counterparts.

By default, the diff routine used is the one built into the p4 command-line application. To change this diff routine to an external diff program, set the P4DIFF environment variable to point to the new program.



Pass options to the underlying diff routine (see Usage Notes for details).


Force the diff (if no revision is specified, against the head revision), even when the client file is not open for edit.

-m max

Limit output to diffs (or status) of only the first max files, unless the -s option is used, in which case the -m option is ignored.


Limit output to only those files that differ.


Pass display options to the underlying diff routine (see Usage Notes for details).


Diff the revisions even if the files are not of type text.


See “Global Options”.

Usage Notes

Can File Arguments Use Revision Specifier?

Can File Arguments Use Revision Range?

Minimal Access Level Required




  • The -doptions supported by p4 diff are:




    ignore changes made within whitespace; this option implies -dl.


    context output format, showing line number ranges and num lines of context around the changes.


    ignore line-ending (CR/LF) convention when finding diffs.


    RCS output format, showing additions and deletions made to the file and associated line ranges.


    summary output format, showing only the number of chunks and lines added, deleted, or changed.


    unified output format, showing added and deleted lines with num lines of context, in a form compatible with the patch(1) utility.


    ignore whitespace altogether; this option implies -dl.

  • The -soptions supported by p4 diff are:




    Show only the names of opened files that are different from the revision in the depot, or are missing.


    Show only the names of files opened for integrate that have been resolved, but that have been modified after being resolved.


    Show only the names of unopened files that are missing from the client workspace, but present in the depot.


    Show only the names of unopened files in the client workspace that are different than the revision in the depot.

    -sl file …

    Every unopened file is compared with the depot, and listed with a status of same, diff, or missing.

    If you use the -f option together with the -sl option, files that are open for edit are also compared and their status is listed.


    Show only the names of opened files in the client workspace that are identical to the revision in the depot.

  • To pass more than one option to the diff routine, group them together. For example:

    p4 diff -dub file

    specifies a unified diff that ignores changes in whitespace.

  • The header line of a unified diff produced with the -du option for use with patch(1) displays filenames in Perforce syntax, not local syntax.

  • If a revision is provided in the file specification, the -s options compare the file(s) regardless of whether they are opened in a changelist or the workspace has been synced to the specified revision.


p4 diff file#5

Compare the client workspace revision of file file to the fifth depot revision.

p4 diff @1999/05/22

Compare all open files in the client workspace to the revisions in the depot as of midnight on May 22, 1999.

p4 diff -du file

Run the comparison on file file, displaying output in a format suitable for the patch(1) utility.

p4 diff -sr | p4 -x - revert

Revert all open, unchanged files.

This differs from p4 revert -a (revert all unchanged files, where resolving a file, even if no changes are made, counts as a change), in that it reverts files whose workspace content matches the depot content, including resolved files that happen to be identical to those in the depot.

The first command shows all open, unchanged files. The second command (running p4 -x and taking arguments, one per line, from standard input, abbreviated as "-") reverts each file in that list.

(This is the UNIX version of this command; it uses a pipe. Most operating systems have some equivalent way of performing these operations in series).

For more information about the -x option to p4, see “Global Options”.

Related Commands

To compare two depot revisions

p4 diff2

To view the entire contents of a file

p4 print