Why do we use .gitignore file? Learn about gitignore
A .gitignore
file is a plain text file where each line contains a pattern for files/directories to ignore. Generally, this is placed in the root folder of the repository, and that's what I recommend. However, you can put it in any folder in the repository and you can also have multiple .gitignore
files. The patterns in the files are relative to the location of that .gitignore
file.
What Files Should be Ignored?
Ignored files are usually platform-specific files or automatically created files from the build systems. Some common examples include:
- Runtime files such as log, lock, cache, or temporary files.
- Files with sensitive information, such as passwords or API keys.
- Compiled code, such as
.class
or.o
. - Dependency directories, such as
/vendor
or/node_modules
. - Build directories, such as
/public
,/out
, or/dist
. - System files like
.DS_Store
orThumbs.db
- IDE or text editor configuration files.
warning:- when the default content of the file depending on how the file was created can not be ignored by .gitignorefile.
.gitignore
Patterns
.gitignore
is a plain text file in which each line contains a pattern for files or directories to ignore.
It uses globbing patterns to match filenames with wildcard characters. If you have files or directories containing a wildcard pattern, you can use a single backslash (\
) to escape the character.
Globbing lets you use special characters to match patterns/characters. In the .gitignore
file, you can use the following:
- blank lines can be used for spacing
#
- marks line as a comment*
- matches 0 or more characters?
- matches 1 character[abc]
- matches a, b, _or_ c**
- matches nested directories -a/**/z
matches- a/z
- a/b/z
- a/b/c/z
Comments
Lines starting with a hash mark (#
) are comments and are ignored. Empty lines can be used to improve the readability of the file and to group related lines of patterns.
Literal File Names
The easiest pattern is a literal file name, for example:
1 .DS_Store
This will ignore any files named .DS_Store
, which is a common file on macOS.
Directories
You can ignore entire directories, just by including their paths and putting a /
on the end:
1 node_modules/
2 logs/
If you leave the slash off of the end, it will match both files and directories with that name.
Wildcard
The *
matches 0 or more characters (except the /
). So, for example, *.log
matches any file ending with the .log
extension.
Another example is *~
, which matches any file ending with ~
, such as index.html~
You can also use the ?
, which matches any one character except for the /
.
Negation
You can use a prefix of !
to negate a file that would be ignored.
1 *.log
2 !example.log
In this example, example.log
is not ignored, even though all other files ending with .log
are ignored.
But be aware, you can’t negate a file inside of an ignored directory:
1 logs/
2 !logs/example.log
Due to performance reasons, git will still ignore logs/example.log
here because the entire logs
directory is ignored.
Double Asterisk
**
can be used to match any number of directories.
**/logs
matches all files or directories named logs (same as the patternlogs
)**/logs/*.log
matches all files ending with.log
in a logs directorylogs/**/*.log
matches all files ending with.log
in the logs directory and any of its subdirectories
**
can also be used to match all files inside of a directory, so for example logs/**
matches all files inside of logs.
Conclusion:-
To recap, the .gitignore
file is used to tell Git about the files that Git should not track. This file should be placed in the same directory that the .git
directory is in.