Invoking diff3

The diff3 command compares three files and outputs descriptions of their differences. Its arguments are as follows:

diff3 options... mine older yours

The files to compare are mine, older, and yours. At most one of these three file names may be `-', which tells diff3 to read the standard input for that file.

An exit status of 0 means diff3 was successful, 1 means some conflicts were found, and 2 means trouble.

• diff3 Options: Summary of options to diff3.

Options to diff3

Below is a summary of all of the options that GNU diff3 accepts. Multiple single letter options (unless they take an argument) can be combined into a single command line argument.

`-a'

Treat all files as text and compare them line-by-line, even if they do not appear to be text. See section Binary Files and Forcing Text Comparisons.

`-A'

Incorporate all changes from older to yours into mine, surrounding all conflicts with bracket lines. See section Marking Conflicts.

`-e'

Generate an ed script that incorporates all the changes from older to yours into mine. See section Selecting Which Changes to Incorporate.

`-E'

Like `-e', except bracket lines from overlapping changes' first and third files. See section Marking Conflicts. With `-e', an overlapping change looks like this:

<<<<<<< mine
lines from mine
=======
lines from yours
>>>>>>> yours

`--ed'

Generate an ed script that incorporates all the changes from older to yours into mine. See section Selecting Which Changes to Incorporate.

`--easy-only'

Like `-e', except output only the nonoverlapping changes. See section Selecting Which Changes to Incorporate.

`-i'

Generate `w' and `q' commands at the end of the ed script for System V compatibility. This option must be combined with one of the `-AeExX3' options, and may not be combined with `-m'. See section Saving the Changed File.

`--initial-tab'

Output a tab rather than two spaces before the text of a line in normal format. This causes the alignment of tabs in the line to look normal. See section Preserving Tabstop Alignment.

`-L label'

`--label=label'

Use the label label for the brackets output by the `-A', `-E' and `-X' options. This option may be given up to three times, one for each input file. The default labels are the names of the input files. Thus `diff3 -L X -L Y -L Z -m A B C' acts like `diff3 -m A B C', except that the output looks like it came from files named `X', `Y' and `Z' rather than from files named `A', `B' and `C'. See section Marking Conflicts.

`-m'

`--merge'

Apply the edit script to the first file and send the result to standard output. Unlike piping the output from diff3 to ed, this works even for binary files and incomplete lines. `-A' is assumed if no edit script option is specified. See section Generating the Merged Output Directly.

`--overlap-only'

Like `-e', except output only the overlapping changes. See section Selecting Which Changes to Incorporate.

`--show-all'

Incorporate all unmerged changes from older to yours into mine, surrounding all overlapping changes with bracket lines. See section Marking Conflicts.

`--show-overlap'

Like `-e', except bracket lines from overlapping changes' first and third files. See section Marking Conflicts.

`-T'

Output a tab rather than two spaces before the text of a line in normal format. This causes the alignment of tabs in the line to look normal. See section Preserving Tabstop Alignment.

`--text'

Treat all files as text and compare them line-by-line, even if they do not appear to be text. See section Binary Files and Forcing Text Comparisons.

`-v'

`--version'

Output the version number of diff3.

`-x'

Like `-e', except output only the overlapping changes. See section Selecting Which Changes to Incorporate.

`-X'

Like `-E', except output only the overlapping changes. In other words, like `-x', except bracket changes as in `-E'. See section Marking Conflicts.

`-3'

Like `-e', except output only the nonoverlapping changes. See section Selecting Which Changes to Incorporate.