p4 merge

MergeClosed 1. To create new files from existing files, preserving their ancestry (branching). 2. To propagate changes from one set of files to another. 3. The process of combining the contents of two conflicting file revisions into a single file, typically using a merge tool, such as P4Merge. one set of files (and/or the stream spec) into another.


p4 [g-opts] merge [-c change] [-m max] [-K -n -Ob -q -F] [--from stream] 
p4 [g-opts] merge [-c change] [-m max] [-K -n -Ob -q] fromFileSpec[revSpec] toFileSpec

For streams:

p4 [g-opts] merge -S stream [-As | -Af]

Syntax conventions


Merging files

The p4 merge command is a simplified form of the p4 integrate command. p4 merge merges a set of changes from source to target files. The command outputs the scheduled resolves. This command is intended for use with streams and distributed version control, but is also usable for traditional Helix Server branches.

In most cases, you can use the p4 merge and p4 copy commands to propagate changes between streams (or branches).

With no arguments, the target defaults to the stream associated with the current stream client, and the source defaults to the current stream parent.

You can specify a different source with --from stream_name, which is an alias for the -P option. You can specify the stream as a directory name relative to the current stream depot. For example, --from main instead of --from //Ace/main.

Using the client workspace as a staging area, p4 merge schedules all affected target files to be resolved per changes in the source. Target files outside of the current client view are not affected. Source files need not be within the client view.

Each file in the target is mapped to a file in the source. Mapping adjusts automatically for files that have been moved or renamed, as long as p4 move was used to move or rename the files. The scope of source and target files sets must include both old-named and new-named files for mappings to be adjusted. Moved source files can schedule moves to be resolved in target files. You can limit the revisions to be merged using the revSpec parameter.

An error message appears if the scope does not include both the old and the new files. For example, an error message appears if you run the merge on a single file that is either the move/add or move/delete of the move pair of actions.

Merging streams

With streams, use p4 merge to keep a child stream up to date with a more stable parent stream. This ensures that when you promote changes back to the stable parent, you do not inadvertently overwrite any other changes that were checked into the parent. Files are opened in a pending changelist and scheduled for resolve as required. To update the parent stream, resolve and submit. By default, p4 merge merges changes into the current stream from its parent, or from another stream specified by the --from option. The source and target can also be specified on the command line as a pair of file paths. More complex merge mappings can be specified using branch specifications as with p4 integrate.

Use the -F option to force merging against a stream’s expected flow. You can also use this option to force the generation of a branch view based on a virtual stream. The mapping itself refers to the underlying real stream.

stream spec

p4 merge -S stream merges fields from the source stream spec into the target stream spec if those fields have been set to propagate with p4 streamspec.

The target stream spec becomes opened for edit, along with stream files. Use p4 merge -S stream -As to merge the stream spec only, and p4 merge -S stream -Af to merge files only.


The p4 integrate and p4 merge commands select (as the base) the revision with the most edits in common with the source and the target.


-c change

Specifies an existing pending changelist in which the files are to be opened.


Force merge operation. Perform the operation when the target stream is not configured to accept a merge from the source. To determine a stream’s expected flow of change, use p4 istat.

--from stream

Specifies a stream other than the parent stream to merge from.

-P is an alias for --from stream

-K Suppress keyword expansion when updating +k type files on the client. See File type modifiers.

-m max

Limits the number of files merged. This option is useful for scripts that integrate large number of files. It enables them to batch the integrations and minimize the locking-related impact to other users of the shared versioning service.


Preview the merge.


The -Ob option displays the base revision for the merge (if any) along with each scheduled resolve.


Quiet mode, which suppresses normal output messages about the list of files being integrated, copied, or merged. Messages regarding errors or exceptional conditions are displayed.

-S stream

Merges fields from the source stream spec into the target stream spec if those fields have been set to propagate with p4 streamspec.

The target stream spec becomes opened for edit, along with stream files.

To merge the stream spec only, use p4 merge -S stream -As

To merge files only, use p4 merge -S stream -Af


See Global options.

Usage Notes

Can File Arguments Use Revision Specifier? Can File Arguments Use Revision Range? Minimal Access Level Required






p4 merge //mySourceBranch/... //myTargetBranch/...
p4 resolve
p4 submit -d "Merge from source branch to target branch"

Merge from the specified source branch to the specified target branch.


p4 merge
p4 resolve
p4 submit -d "Merge latest changes from parent stream"

Merge into the current stream from its parent.

p4 merge --from //Ace/rel1
p4 resolve
p4 submit -d "Merge from release"

Merge into the current stream from the //Ace/rel1 stream.

p4 merge @100,104
p4 resolve
p4 submit -d "Merge five changes from parent"

Merge changes 100 through 104 from the parent stream into the current stream.

Related Commands

Promote changes to more stable neighbor stream

p4 copy

Propagate changes

p4 integrate

Resolve file conflicts

p4 resolve