Git Ignore Patterns

 .gitignore uses globbing patterns to match against file names. 
 A gitignore file specifies intentionally untracked files that Git should ignore. Files already tracked by Git are not affected;

Each line in a gitignore file specifies a pattern. When deciding whether to ignore a path, Git normally checks gitignore patterns from multiple sources, with the following order of precedence, from highest to lowest (within one level of precedence, the last matching pattern decides the outcome):

• Patterns read from the command line for those commands that support them.
  
• Patterns read from a .gitignore file in the same directory as the path, or in any parent directory, with patterns in the higher level files (up to the toplevel of the work tree) being overridden by those in lower level files down to the directory containing the file. These patterns match relative to the location of the .gitignore file. A project normally includes such .gitignore files in its repository, containing patterns for files generated as part of the project build.
  
• Patterns read from $GIT_DIR/info/exclude.
  
• Patterns read from the file specified by the configuration variable core.excludesFile.
  

Which file to place a pattern in depends on how the pattern is meant to be used.

• Patterns which should be version-controlled and distributed to other repositories via clone (i.e., files that all developers will want to ignore) should go into a .gitignore file.
  
• Patterns which are specific to a particular repository but which do not need to be shared with other related repositories (e.g., auxiliary files that live inside the repository but are specific to one user’s workflow) should go into the $GIT_DIR/info/exclude file.
  
• Patterns which a user wants Git to ignore in all situations (e.g., backup or temporary files generated by the user’s editor of choice) generally go into a file specified by core.excludesFile in the user’s ~/.gitconfig. Its default value is $XDG_CONFIG_HOME/git/ignore. If $XDG_CONFIG_HOME is either not set or empty, $HOME/.config/git/ignore is used instead.
  

The underlying Git plumbing tools, such as git ls-files and git read-tree, read gitignore patterns specified by command-line options, or from files specified by command-line options. Higher-level Git tools, such as git status and git add, use patterns from the sources specified above.

PATTERN FORMAT

• A blank line matches no files, so it can serve as a separator for readability.
  
• A line starting with # serves as a comment. Put a backslash ("\") in front of the first hash for patterns that begin with a hash.
  
• Trailing spaces are ignored unless they are quoted with backslash ("\").
  
• An optional prefix "!" which negates the pattern; any matching file excluded by a previous pattern will become included again. It is not possible to re-include a file if a parent directory of that file is excluded. Git doesn’t list excluded directories for performance reasons, so any patterns on contained files have no effect, no matter where they are defined. Put a backslash ("\") in front of the first "!" for patterns that begin with a literal "!", for example, "\!important!.txt".
  
• If the pattern ends with a slash, it is removed for the purpose of the following description, but it would only find a match with a directory. In other words, foo/ will match a directory foo and paths underneath it, but will not match a regular file or a symbolic link foo (this is consistent with the way how pathspec works in general in Git).
  
• If the pattern does not contain a slash /, Git treats it as a shell glob pattern and checks for a match against the pathname relative to the location of the .gitignore file (relative to the toplevel of the work tree if not from a .gitignore file).
  
• Otherwise, Git treats the pattern as a shell glob: "*" matches anything except "/", "?" matches any one character except "/" and "[]" matches one character in a selected range. See fnmatch(3) and the FNM_PATHNAME flag for a more detailed description.
  
• A leading slash matches the beginning of the pathname. For example, "/*.c" matches "cat-file.c" but not "mozilla-sha1/sha1.c".
  

Two consecutive asterisks ("**") in patterns matched against full pathname may have special meaning:

• A leading "**" followed by a slash means match in all directories. For example, "**/foo" matches file or directory "foo" anywhere, the same as pattern "foo". "**/foo/bar" matches file or directory "bar" anywhere that is directly under directory "foo".
  
• A trailing "/**" matches everything inside. For example, "abc/**" matches all files inside directory "abc", relative to the location of the .gitignore file, with infinite depth.
  
• A slash followed by two consecutive asterisks then a slash matches zero or more directories. For example, "a/**/b" matches "a/b", "a/x/b", "a/x/y/b" and so on.
  
• Other consecutive asterisks are considered regular asterisks and will match according to the previous rules.
  

You can construct your patterns using various symbols:
 ** these explanations assume your .gitignore file is in the top level directory of your repository, as is the convention.

Pattern	Example matches	Explanation*
**/logs	logs/debug.log logs/monday/foo.bar build/logs/debug.log	You can prepend a pattern with a double asterisk to match directories anywhere in the repository.
**/logs/debug.log	logs/debug.log build/logs/debug.log but not logs/build/debug.log	You can also use a double asterisk to match files based on their name and the name of their parent directory.
*.log	debug.log foo.log .log logs/debug.log	An asterisk is a wildcard that matches zero or more characters.
*.log !important.log	debug.log trace.log but not important.log logs/important.log	Prepending an exclamation mark to a pattern negates it. If a file matches a pattern, but also matches a negating pattern defined later in the file, it will not be ignored.
*.log !important/*.log trace.*	debug.log important/trace.log but not important/debug.log	Patterns defined after a negating pattern will re-ignore any previously negated files.
/debug.log	debug.log but not logs/debug.log	Prepending a slash matches files only in the repository root.
debug.log	debug.log logs/debug.log	By default, patterns match files in any directory
debug?.log	debug0.log debugg.log but not debug10.log	A question mark matches exactly one character.
debug[0-9].log	debug0.log debug1.log but not debug10.log	Square brackets can also be used to match a single character from a specified range.
debug[01].log	debug0.log debug1.log but not debug2.log debug01.log	Square brackets match a single character form the specified set.
debug[!01].log	debug2.log but not debug0.log debug1.log debug01.log	An exclamation mark can be used to match any character except one from the specified set.
debug[a-z].log	debuga.log debugb.log but not debug1.log	Ranges can be numeric or alphabetic.
logs	logs logs/debug.log logs/latest/foo.bar build/logs build/logs/debug.log	If you don't append a slash, the pattern will match both files and the contents of directories with that name. In the example matches on the left, both directories and files named logs are ignored
logs/	logs/debug.log logs/latest/foo.bar build/logs/foo.bar build/logs/latest/debug.log	Appending a slash indicates the pattern is a directory. The entire contents of any directory in the repository matching that name – including all of its files and subdirectories – will be ignored
logs/ !logs/important.log	logs/debug.log logs/important.log	Wait a minute! Shouldn't logs/important.log be negated in the example on the left Nope! Due to a performance-related quirk in Git, you can not negate a file that is ignored due to a pattern matching a directory
logs/**/debug.log	logs/debug.log logs/monday/debug.log logs/monday/pm/debug.log	A double asterisk matches zero or more directories.
logs/*day/debug.log	logs/monday/debug.log logs/tuesday/debug.log but not logs/latest/debug.log	Wildcards can be used in directory names as well.
logs/debug.log	logs/debug.log but not debug.log build/logs/debug.log	Patterns specifying a file in a particular directory are relative to the repository root. (You can prepend a slash if you like, but it doesn't do anything special.)

 

Example to exclude everything except a specific directory foo/bar (note the /* - without the slash, the wildcard would also exclude everything within foo/bar):

    $ cat .gitignore
    # exclude everything except directory foo/bar
    /*
    !/foo
    /foo/*
    !/foo/bar

In addition to these characters, you can use # to include comments in your .gitignore file:
# ignore all logs 

*.log

 

 

 

You can use \ to escape .gitignore pattern characters if you have files or directories containing them:

# ignore the file literally named foo[01].txt
foo\[01\].txt

 

 

 

Posted in: GIT