Git Show
What is git-show?
git-show is a command line utility that is used to view expanded details on Git objects such as blobs, trees, tags, and commits. git-show has specific behavior per object type.
Tags show the tag message and other objects included in the tag. Trees show the names and content of objects in a tree. Blobs show the direct content of the blob. Commits show a commit log message and a diff output of the changes in the commit.
Git objects are all accessed by references. By default, git-show acts against the HEAD reference. The HEAD reference always points to the last commit of the current branch. Therefore, you can use git-show to display the log message and diff output of the latest commit.
Git-show options
<object>…
A reference to an object or a list of objects may be passed to examine those specific objects. If no explicit objects are passed, git-show defaults to the HEAD reference.
--pretty[=<format>]
The pretty option takes a secondary format value that can be one of: oneline, short, medium, full, fuller, email, raw, and format:<string>. If omitted, the format defaults to medium. Each format option is a different template for how Git formats the show output. The <code>oneline</code> option can be very helpful for showing a list of commits
--abbrev-commit
This option shortens the length of output commit IDs. Commit IDs are 40 characters long and can be hard to view on narrow terminal screens. This option combined with --pretty=oneline can produce a highly succinct git log output.
--no-abbrev-commit
Always Show the full 40 character commit ID. This will ignore --abbrev-commit and any other options that abbreviate commit IDs like the --oneline format
--oneline
This is a shortcut for using the expanded command --pretty=oneline --abbrev-commit
--encoding[=<encoding>]
Character encoding on Git log messages defaults to UTF-8. The encoding option can change to a different character encoding output. This is useful if you are working with Git in an environment with different character encoding, like an Asian language terminal.
>--expand-tabs=<n>
--expand-tabs
--no-expand-tabs
These options replace tab characters with spaces in the log message output. The n value can be set to configure how many space characters the tabs expand to. Without an explicit n value tabs will expand to 8 spaces. --no-expand-tabs is equivalent to n=0
--notes=<ref>
--no-notes
Git has a note system that enables arbitrary ‘note’ metadata to be attached to objects. This data can be hidden or filtered when using git-show.
--show-signature
This option will validate the commit is signed with an encrypted signature by passing it to a gpg subcommand.
Pretty formats for git-show
The --pretty option discussed above accepts several secondary options to massage the format of git-show output. These secondary options are listed below with example template
- oneline
<sha1> <title line>
Oneline attempts to compact as much info into a single line as possible
- short
commit <sha1>
Author: <author>
<title line>
- medium
commit <sha1>
Author: <author>
Date: <author date>
<title line>
<full commit message>
- full
commit <sha1>
Author: <author>
Commit: <committer>
<title line>
<full commit message>
- fuller
commit <sha1>
Author: <author>
AuthorDate: <author date>
Commit: <committer>
CommitDate: <committer date>
<title line>
<full commit message>
- email
From <sha1> <date>
From: <author>
Date: <author date>
Subject: [PATCH] <title line>
<full commit message>
- raw
raw format ignores other direct formatting options passed togit-showand outputs the commit exactly as stored in the object. Raw will disregard--abrevand--no-abbrevand always show the parent commits.
- format:
format enables the specification of a custom output format. It works similar to the C language’sprintfcommand. The--pretty=formatoption takes a secondary value of a template string. The template has access to placeholder variables that will be filled with data from the commit object. These placeholders are listed below:
• %H: commit hash
• %h: abbreviated commit hash
• %T: tree hash
• %t: abbreviated tree hash
• %P: parent hashes
• %p: abbreviated parent hashes
• %an: author name
• %aN: author name
• %ae: author email
• %aE: author email
• %ad: author date (format respects --date= option)
• %aD: author date, RFC2822 style
• %ar: author date, relative
• %at: author date, UNIX timestamp
• %ai: author date, ISO 8601 format
• %cn: committer name
• %cN: committer name
• %ce: committer email
• %cE: committer email
• %cd: committer date
• %cD: committer date, RFC2822 style
• %cr: committer date, relative
• %ct: committer date, UNIX timestamp
• %ci: committer date, ISO 8601 format
• %d: ref names, like the --decorate option of git-log(1)
• %e: encoding
• %s: subject
• %f: sanitized subject line, suitable for a filename
• %b: body
• %N: commit notes
• %gD: reflog selector, e.g., refs/stash@{1}
• %gd: shortened reflog selector, e.g., stash@{1}
• %gs: reflog subject
• %Cred: switch color to red
• %Cgreen: switch color to green
• %Cblue: switch color to blue
• %Creset: reset color
• %C(...): color specification, as described in color.branch.* config option
• %m: left, right or boundary mark
• %n: newline
• %%: a raw %
• %x00: print a byte from a hex code
• %w([<w>[,<i1>[,<i2>]]]): switch line wrapping, like the -w option of git-shortlog
Examples of git-show
git show --pretty="" --name-only bd61ad98This will list all the files that were touched in a commit
git show REVISION:path/to/fileThis will show a specific version of a file. Replace the REVISON with a Git sha.
git show v2.0.0 6ef002d74cbbc099e1063728cab14ef1fc49c783This will show the v2.0.0 tag and also commit at 6ef002d74cbbc099e1063728cab14ef1fc49c783
git show commitA...commitDThis will output all commits in the range from commitA to commit D
Summary
git-show is a very versatile command for examining objects in a Git repo. It can be used to target specific files at specific revisions. Examining a commit range with git-show will output all the individual commits between the range. git-show can be a helpful tool for creating patch notes and tracking changes in a repository.
