Executing Commands with find

• Commands can be executed on found files
  • command must be preceded with -exec or -ok
    • -ok prompts before acting on each file
  • Command must end with Space\;
  • Can use {} as a filename placeholder
  • find -size +100M -ok mv {} /tmp/largefiles/ \;

Using the -exec or -ok options with find will cause find to execute a command once for each file that matches the given criteria. This is commonly used for things like removing files or renaming files to have a certain extension. Be extremely careful when using -exec because it may perform the action on many files (remember that find recourses through subdirectories) and it does not ask for confirmation. Remember that running the search without -exec will list all matches, thus allowing you to preview which files will be acted upon. Alternately you can use the -ok option, which causes find to ask for each file.

The reason that the commands given with -exec and -ok must end in a \; is because find uses ; as the delimiting character. Unfortunately ; is also a delimiting character for the shell so we must prevent bash from interpreting it. When a character is prepended with a backslash (\), bash is instructed to treat it literally, so typing \; at the bash command prompt will send ; to find after bash has done its interpretation.

Find Execution Examples: –

• Back up configuration files, adding a .orig extension
  $ find -name '*.conf' -exec cp {} {}.orig \;
• Prompt to remove joe’s tmp files that are over 3 days old
  $ find /tmp -ctime +3 -user joe -ok rm {} \;
• Fix other-writable files in your home directory
  $ find ~ -perm -002 -exec chmod o-w {} \;
• Do an ls -l style listing of all directories in /home/
  $ find /home -type d -ls
• Find files that end in .sh but are not executable by anyone. For each file, ask to make it executable by everyone
  $ find -not -perm +111 -name ‘*.sh’ -ok chmod 755 {} \;

You can use find to execute any command you would like, and if you use the {} as filename place holders, the find command will put the file name of a file it has found in place of {} and execute the command.