Searching for Files

locate

$ locate *.txt         # 在 index 中搜索文件
$ locate -i some*.txt  # 忽略大小写
$ sudo updatedb        # 更新 index 文件

find

find [starting-point]... [option]... [operator]... [test]... [action]...

• If no starting-point is specified, . is assumed.

  Tests

  | Test | Description | | —- | —- | | -name pattern | Match files and directories with the specified wildcard pattern. | | -type c | Match files of type c. See File Types. | | -size [+|-]n | Match files of size n. See Size Units | | -perm [-|/]mode | Match files or directories that have permissions set to the specified mode. mode can be expressed by either octal or symbolic notation.
  - mode 精确匹配 mode 指定的权限
  - find . -perm 644
  - find . -perm u=rw,g=r,o=r
  - find . -perm ugo=rw
  - -mode 至少包括 mode 指定的权限
  - find . -perm -220
  - find . -perm -g+w,u+w
  - /mode 满足 mode 指定的权限中的一个即可
  - find . -perm /220
  - find . -perm /u+w,g+w
  - find . -perm /u=w,g=w
  | | -cmin n | Match files or directories whose content or attributes were last modified exactly n minutes ago. To specify less than n minutes ago, use -n, and to specify more than n minutes ago, use +n. | | -cnewer file | Match files or directories whose contents or attributes were last modified more recently than those of file. | | -ctime n | Match files or directories whose contents or attributes were last modified n24 hours ago. | | -empty | Match empty files and directories. | | -group name | Match file or directories belonging to belonging to group name. name may be expressed may be expressed either as a group name or as a numeric group ID. | | -iname pattern | Like the -name test but case-insensitive. | | -inum n | Match files with inode number n. This is helpful for finding all the hard links to a particular inode. | | -mmin n | Match files or directories whose contents were last modified n minutes ago. | | -mtime n | Match files or directories whose contents were last modified n24 hours ago. | | -newer file | Match files and directories whose contents were modified more recently than the specified file. This is useful when writing shell scripts that perform file backups. Each time you make a backup, update a file (such as a log) and then use find to determine which files have changed since the last update. | | -nouser | Match file and directories that do not belong to a valid user. This can be used to find files belonging to deleted accounts or to detect activity by attackers. | | -nogroup | Match files and directories that do not belong to a valid group. | | -samefile name | Similar to the -inum test. Match files that share the same inode number as file name. | | -user name | Match files or directories belonging to user name. The user may be expressed by a username or by a numeric user ID. |

File Types

Size Units

Operators

Actions

Predefined Actions

User-Defined Actions

find ... -exec COMMAND \{\} \;
find ... -exec COMMAND '{}' ';'

• COMMAND is the name of a command,
• {} is a symbolic representation of the current pathname,
• The semicolon is a required delimiter indicating the end of the command.

find ... -ok COMMAND '{}' ';'

• Execute a user-defined action interactively.

• By using the -ok action in place of -exec, the user is prompted before execution of each specified command.

  Combine Results with +

  find ~ -type f -name 'foo*' -exec ls -l '{}' +

• By changing the trailing semicolon character to a plus sign, we activate the capability of find to combine the results of the search into an argument list for a single execution of the desired command.

  Combine Results with xargs

  find ~ -type f -name 'foo*' -print | xargs ls -l

• xargs accepts input from standard input and converts it into an argument list for a specified command.

• --null or -0 : Accept null-separated input(filenames containing embedded spaces)

  Options

  | Option | Description | | —- | —- | | -depth | Direct find to process a directory’s files before the directory itself. This option is automatically applied when the -delete action is specified. | | -maxdepth levels | Set the maximum number of levels that find will descend into a directory tree when performing tests and actions. | | -mindepth levels | Set the minimum number of levels that find will descend into a directory tree before applying tests and actions. | | -mount | Direct find not to traverse directories that are mounted on other file systems. | | -noleaf | Direct find not to optimize its search based on the assumption that it is searching a Unix-like file system. This is needed when scanning DOS/Windows file systems and CD-ROMs. |