Introduction and usage of find command
Find: file lookup
Function: real-time search tool, complete question search by traversing the specified path, and recursively process files in the hierarchical directory
Characteristics of find:
1. Accurate search, real-time search 2. It is possible to search only directories 3. 5 for which the user has read and execute permissions. The speed of searching is a little slower.
Find (nothing to follow will show all the lists in the current directory. Find is searched recursively by default)
Syntax: find [OPTION]... [search path] [search condition] [processing action]
Find path: specify a specific target path; default is the current directory
Search criteria: specified search criteria, such as file name, size, type, permissions, etc.; default is to find all files under the specified path
Processing action: operate on files that meet the criteria, and output to the screen by default
Options:
Search directory level
-maxdepth level: maximum search directory depth-mindepth level: minimum search directory depth example: find directory-maxdepth 2-mindepth 2: search only level 2 directories-depth:find directories-depth: process files first and then process directories
Look up by file name and inode:
-name "file name": support the use of glob *,?, [], [^]-iname "file name": case-insensitive-inum n search by inode number
Example:
[root@localhost data] $find / data-inum 67
/ data/123.txt
-samefile name files with the same inode number
Example:
Find / data-samefile / data/fi.sh: directories can be inconsistent before and after viewing files with the same node number
The directory in which the standard files are searched
-links n files with n links-regex "PATTERN": matches the entire file path with PATTERN instead of the file name (matches the full path)
Search according to the document owner and subordinate group
-user username: find files with specified user ownership-group groupname: find files with specified group ownership-uid useruid: find files with specified UID owner-gid groupgid: find files with specified GID ownership group-nouser: find files without ownership-nogroup: find files without group ownership
Look up by file type:
-type:
B special block file (buffered) c special character file (unbuffered) d directory p named pipe (FIFO) f ordinary file l symbolic link s socket
Empty file or directory
-empty
-type d-empty
Depending on the file size:
-size: commonly used units (K M G c (Byte))
+ # M: indicates a file greater than # M, + 5m
-# M: represents a file less than # M,-5m
Look up according to time:
In days:
-atime: access time
+, -: + 10, files visited in more than ten days,-files accessed in ten days
-mtime: modification time, time when the file content was last modified, and file content modification
-ctime: change time, last change time of the file, attribute and file name change
In minutes:
-amin: access time
-mmin: modification time
-cmin: change the time
Find based on file permissions:
-perm:
Mode: precise search
/ mode: the permission of any kind of object meets the condition as long as it matches one bit. Or the relationship between. In the early days, it was indicated by a + sign.
-mode: each type of object must have the specified permission to meet the condition
0: does not care
For example: find-perm 755 file, which exactly matches the file with permission 755
Find-perm / 222file, owner, group, others, one of whom has write permission to match
Find-perm-22222 file, owner, group, others, each must have write access to match
Find-perm-002file, which is matched only if others have write permission
Action:
-print: default processing action to display the matching to the screen
-ls: similar to ls-l viewing files
-delete: delete the matching content (dangerous, do not use it)
-fls file: the found file is saved to the specified file with long format information
-ok command {}\;: execute the command specified by the command bit for the found file. The disadvantage is that you need to confirm before executing the command on each matching file.
Example: find / data-name "* .sh"-ok mv {} / tmp\
{}: reference the file matched by the previous find, and refer to the name of the file found, for example, the file name matched within ping.sh,name {} {ping.sh}
\;: syntax format, which must end with\;
-exec command {}\;: execute the command specified by the command bit for the found file. Unlike ok, a confirmation is not required.
Example: find / data-name "* .sh"-ok mv {} .bak / tmp\
{} .bak: move to the / tmp directory to rename the file with the suffix .bak
Find all files in the / var/ directory that do not belong to root, lp, gdm
[root@centos7 ~] # find / var!-user root!-user lp!-user gdm-type f
/ var/lib/colord/mapping.db
/ var/lib/colord/storage.db
/ var/lib/nfs/state
/ var/lib/unbound/root.key
/ var/lib/setroubleshoot/setroubleshoot_database.xml
/ var/lib/setroubleshoot/email_alert_recipients
/ var/lib/postfix/master.lock
/ var/spool/mail/rpc
/ var/spool/mail/cheng
/ var/spool/mail/ning
