使用/ config . php。

从文档中可以看到:

如果模式不包含斜杠/，git将其视为shell glob模式，并根据相对于.gitignore文件位置的路径名(如果不是来自.gitignore文件，则相对于工作树的顶层)检查匹配。 前导斜杠匹配路径名的开头。例如，“/*.c”匹配“cat-file.c”，但不匹配“mozilla-sha1/sha1.c”。

所以你应该在你的根目录.gitignore后面加上下面这行代码:

/config.php

如果上面的方法不适合你，试试下面的方法:

#1.1 Do NOT ignore file pattern in  any subdirectory
!*/config.php
#1.2 ...only ignore it in the current directory
/config.php

##########################

# 2.1 Ignore file pattern everywhere
config.php
# 2.2 ...but NOT in the current directory
!/config.php

旧版本的git要求您首先定义一个忽略模式，然后立即(在下一行)定义排除。[在1.9.3版本上测试(Apple Git-50)]

/config.php
!/*/config.php

后续版本只需要以下[在版本2.2.1上测试]

/config.php

一个wordpress站点的例子，但基本上忽略所有内容，然后添加异常从!包括什么

# Ignore everything in the root except the "wp-content" directory.
/*
!.gitignore
!wp-content/
!wp-config.php
#
# # Ignore everything in the "wp-content" directory, except the "plugins"
# # and "themes" directories.
wp-content/*
!wp-content/plugins/
!wp-content/themes/
#
# # Ignore everything in the "plugins" directory, except the plugins you
# # specify (see the commented-out examples for hints on how to do this.)
wp-content/plugins/*
# # !wp-content/plugins/my-single-file-plugin.php
# # !wp-content/plugins/my-directory-plugin/
#
# # Ignore everything in the "themes" directory, except the themes you
# # specify (see the commented-out example for a hint on how to do this.)
wp-content/themes/*
!wp-content/themes/twentyeleven/