diff options
Diffstat (limited to 'Documentation/diff-format.txt')
| -rw-r--r-- | Documentation/diff-format.txt | 220 |
1 files changed, 62 insertions, 158 deletions
diff --git a/Documentation/diff-format.txt b/Documentation/diff-format.txt index 9709c35c98..400cbb3b1c 100644 --- a/Documentation/diff-format.txt +++ b/Documentation/diff-format.txt @@ -83,161 +83,65 @@ Note that 'combined diff' lists only files which were modified from all parents. -Generating patches with -p --------------------------- - -When "git-diff-index", "git-diff-tree", or "git-diff-files" are run -with a '-p' option, or "git diff" without the '--raw' option, they -do not produce the output described above; instead they produce a -patch file. You can customize the creation of such patches via the -GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS environment variables. - -What the -p option produces is slightly different from the traditional -diff format. - -1. It is preceded with a "git diff" header, that looks like - this: - - diff --git a/file1 b/file2 -+ -The `a/` and `b/` filenames are the same unless rename/copy is -involved. Especially, even for a creation or a deletion, -`/dev/null` is _not_ used in place of `a/` or `b/` filenames. -+ -When rename/copy is involved, `file1` and `file2` show the -name of the source file of the rename/copy and the name of -the file that rename/copy produces, respectively. - -2. It is followed by one or more extended header lines: - - old mode <mode> - new mode <mode> - deleted file mode <mode> - new file mode <mode> - copy from <path> - copy to <path> - rename from <path> - rename to <path> - similarity index <number> - dissimilarity index <number> - index <hash>..<hash> <mode> - -3. TAB, LF, double quote and backslash characters in pathnames - are represented as `\t`, `\n`, `\"` and `\\`, respectively. - If there is need for such substitution then the whole - pathname is put in double quotes. - -The similarity index is the percentage of unchanged lines, and -the dissimilarity index is the percentage of changed lines. It -is a rounded down integer, followed by a percent sign. The -similarity index value of 100% is thus reserved for two equal -files, while 100% dissimilarity means that no line from the old -file made it into the new one. - - -combined diff format --------------------- - -"git-diff-tree", "git-diff-files" and "git-diff" can take '-c' or -'--cc' option to produce 'combined diff', which looks like this: - ------------- -diff --combined describe.c -index fabadb8,cc95eb0..4866510 ---- a/describe.c -+++ b/describe.c -@@@ -98,20 -98,12 +98,20 @@@ - return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1; - } - -- static void describe(char *arg) - -static void describe(struct commit *cmit, int last_one) -++static void describe(char *arg, int last_one) - { - + unsigned char sha1[20]; - + struct commit *cmit; - struct commit_list *list; - static int initialized = 0; - struct commit_name *n; - - + if (get_sha1(arg, sha1) < 0) - + usage(describe_usage); - + cmit = lookup_commit_reference(sha1); - + if (!cmit) - + usage(describe_usage); - + - if (!initialized) { - initialized = 1; - for_each_ref(get_name); ------------- - -1. It is preceded with a "git diff" header, that looks like - this (when '-c' option is used): - - diff --combined file -+ -or like this (when '--cc' option is used): - - diff --c file - -2. It is followed by one or more extended header lines - (this example shows a merge with two parents): - - index <hash>,<hash>..<hash> - mode <mode>,<mode>..<mode> - new file mode <mode> - deleted file mode <mode>,<mode> -+ -The `mode <mode>,<mode>..<mode>` line appears only if at least one of -the <mode> is different from the rest. Extended headers with -information about detected contents movement (renames and -copying detection) are designed to work with diff of two -<tree-ish> and are not used by combined diff format. - -3. It is followed by two-line from-file/to-file header - - --- a/file - +++ b/file -+ -Similar to two-line header for traditional 'unified' diff -format, `/dev/null` is used to signal created or deleted -files. - -4. Chunk header format is modified to prevent people from - accidentally feeding it to `patch -p1`. Combined diff format - was created for review of merge commit changes, and was not - meant for apply. The change is similar to the change in the - extended 'index' header: - - @@@ <from-file-range> <from-file-range> <to-file-range> @@@ -+ -There are (number of parents + 1) `@` characters in the chunk -header for combined diff format. - -Unlike the traditional 'unified' diff format, which shows two -files A and B with a single column that has `-` (minus -- -appears in A but removed in B), `+` (plus -- missing in A but -added to B), or `" "` (space -- unchanged) prefix, this format -compares two or more files file1, file2,... with one file X, and -shows how X differs from each of fileN. One column for each of -fileN is prepended to the output line to note how X's line is -different from it. - -A `-` character in the column N means that the line appears in -fileN but it does not appear in the result. A `+` character -in the column N means that the line appears in the last file, -and fileN does not have that line (in other words, the line was -added, from the point of view of that parent). - -In the above example output, the function signature was changed -from both files (hence two `-` removals from both file1 and -file2, plus `++` to mean one line that was added does not appear -in either file1 nor file2). Also two other lines are the same -from file1 but do not appear in file2 (hence prefixed with ` +`). - -When shown by `git diff-tree -c`, it compares the parents of a -merge commit with the merge result (i.e. file1..fileN are the -parents). When shown by `git diff-files -c`, it compares the -two unresolved merge parents with the working tree file -(i.e. file1 is stage 2 aka "our version", file2 is stage 3 aka -"their version"). +include::diff-generate-patch.txt[] + + +other diff formats +------------------ + +The `--summary` option describes newly added, deleted, renamed and +copied files. The `--stat` option adds diffstat(1) graph to the +output. These options can be combined with other options, such as +`-p`, and are meant for human consumption. + +When showing a change that involves a rename or a copy, `--stat` output +formats the pathnames compactly by combining common prefix and suffix of +the pathnames. For example, a change that moves `arch/i386/Makefile` to +`arch/x86/Makefile` while modifying 4 lines will be shown like this: + +------------------------------------ +arch/{i386 => x86}/Makefile | 4 +-- +------------------------------------ + +The `--numstat` option gives the diffstat(1) information but is designed +for easier machine consumption. An entry in `--numstat` output looks +like this: + +---------------------------------------- +1 2 README +3 1 arch/{i386 => x86}/Makefile +---------------------------------------- + +That is, from left to right: + +. the number of added lines; +. a tab; +. the number of deleted lines; +. a tab; +. pathname (possibly with rename/copy information); +. a newline. + +When `-z` output option is in effect, the output is formatted this way: + +---------------------------------------- +1 2 README NUL +3 1 NUL arch/i386/Makefile NUL arch/x86/Makefile NUL +---------------------------------------- + +That is: + +. the number of added lines; +. a tab; +. the number of deleted lines; +. a tab; +. a NUL (only exists if renamed/copied); +. pathname in preimage; +. a NUL (only exists if renamed/copied); +. pathname in postimage (only exists if renamed/copied); +. a NUL. + +The extra `NUL` before the preimage path in renamed case is to allow +scripts that read the output to tell if the current record being read is +a single-path record or a rename/copy record without reading ahead. +After reading added and deleted lines, reading up to `NUL` would yield +the pathname, but if that is `NUL`, the record will show two paths. |