How to recursively go through all local or remote directories

Posted on in Categories CentOS, Linux, programming, Shell scripting, Tips, Ubuntu Linux, UNIX last updated December 2, 2007

You can use find command or recursdir command to recurse through local or remote directories to command/find files or create tar files.

recursdir command pass a C script to recursively perform operations on files. recursdir is an excellent tool for automatic stuff. It provides C style programming functions and statements such as:

  • strncmp()
  • exec()
  • system()
  • strstr()
  • strcat()
  • printf()
  • popen()
  • if ( expr ) { take-action }
  • if ( expr ) { take-action } else { do-something-else; }
  • /* comments */
  • Detecting file types and macros
  • All of the logical, arithmetic and bitwise C operators are supported. These are ( ) >= <= > < != == && || ! - + * / % & ^ and have the same meanings and precedences as in C. etc.

Install recursdir

recursdir is part of mirrordir package:
$ sudo apt-get install mirrordir

Recursively find file and take action

For example find out all *.bak file and delete them, using find command:
find /path/to/dir -iname "*bak" -exec rm {} \;
Following is a fast and overkill equivalent of find, using recursdir :
recursdir /path/to/dir -C 'exec("/bin/rm","-f",PATH);'

Find and print out all the *.CPP (C++) files on your system, enter (note usage of if and printf() C like syntax):
recursdir /path/to/dir -C 'if (!glob ("*.cpp", FILE)) printf ("%s\n", PATH);'
or
find /path/to/dir -iname "*.cpp"

Backup a remote ftp site to local tape:

This is my favorite command to mirror remote ftp tree:
recursdir ftp:[email protected]/ --tar-file /dev/mt

Write complex directory manipulation scripts

You can write complex scripts using recursdir. For example, following will removes all core files from your Linux 32 bit system:

recursdir / -C '
              long l;
              /* look for /proc */
              if (strncmp (PATH, "/proc", 5)) {
                  if (S_ISREG (stat.st_mode) && !strcmp ("core", FILE)) {
                      if (strstr (popen ("file " + PATH), "ELF 32-bit LSB core")) {
                          l = l + stat.st_size;
                          printf ("removing: %s, cumu. total = %ldkB\n", PATH, l >> 10);
                          exec ("rm", "-f", PATH);
                      }
                  }
              }'

recursdir offers many more advanced options such as encryption, backups compression and many more, please refer the man page for more information.

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

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