103.3 Perform basic file management

103.3 Perform basic file management

1. How to Find Files

   • find STARTING_PATH OPTIONS EXPRESSION
     • find . -name "myfile.txt"
     • find /home/frank -name "*.png"
   • Using Criteria to Speed Search with find
     • -type f archivo plano -type d archivo directorio -type l archivo link
       • find . -type d -name "example"
     • criterio
       • -name
       • -iname
       • -not
       • -maxdepth N
   • Locating Files by Modification Time
     • sudo find / -name "*.conf" -mtime 7
   • Locating Files by Size
     • sudo find /var -size +2G
       • -size 100b
         • -size +100k
           • -size -20M
             • -size +2G

2. Acting on the Result Set

   • find . -name "*.conf" -exec chmod 644 '{}' \;

3. Using grep to Filter for Files Based on Content

   • find . -type f -exec grep "lpi" '{}' \; -print
     • find . -name "*.bak" -delete

4. Archiving Files

   • The tar Command (Archiving and Compresssion)
     • --create (-c)
     • --extract (-x)
     • --list (-t)
     • --verbose (-v)
     • --file=archive=name (-f archive-name)

5. tar -cvf archive.tar stuff

   • -c Create an archive.
   • -v Display progress
   • -f Allows to specify the filename of the archive.

6. tar -cvf NAME-OF-ARCHIVE.tar /PATH/TO/DIRECTORY-OR-FILE

   • tar -cvf archive.tar stuff1 stuff2
   • tar -xvf archive.tar
   • tar -xvf archive.tar -C /tmp

7. Compressing with tar

   • tar -czvf name-of-archive.tar.gz stuff
   • tar -cjvf name-of-archive.tar.bz stuff
   • tar -xzvf archive.tar.gz

8. gzip FILE-TO-COMPRESS

   • gzip
     • gunzip
   • bzip2
     • bunzip2

9. The cpio Command

   • ls | cpio -o > archive.cpio
   • cpio -id < archive.cpio

10. The dd Command

    • dd if=oldfile of=newfile
    • dd if=oldfile of=newfile conv=ucase
    • dd if=/dev/sda of=backup.dd bs=4096

11. Guided Exercises

    • find /home/frank/Documents/ -type d
    • tar cvzf /home/frank/backup.tar.gz /home/frank/dir1
    • find /var -name *.backup
    • find /var -name *.backup -size +100M -size -1000M
    • find /var -name *.backup -size +100M -size -1000M -delete
    • tar -cvf db-first-quarter-2018.backup.tar db-jan-2018.backup db-feb-2018.backup db-march-2018.backup db-apr-2018.backup
      • tar -zcvf db-first-quarter-2018.backup.tar.gz db-jan-2018.backup db-feb-2018.backup db-march-2018.backup db-apr-2018.backup

12. Find Criteria

    • -daystart
      • -amin, -atime, -cmin, -ctime, -mmin, and -mtime
        • -amin n
          • File was last accessed n minutes ago.
        • +n for greater than n
        • -n for less than n
        • n for exactly n.
        • -atime n
          • File was last accessed n*24 hours ago
        • -cmin n
          • File's status was last changed n minutes ago
        • -ctime n
          • File's status was last changed n*24 hours ago
        • -a : accesado -c:change, -m:modified

13. Exampes find

    • find /tmp -name core -type f -print | xargs /bin/rm -f
      • los nombres que contienen comillas simples o dobles, espacios o nuevas líneas no se manejan correctamente
    • find /tmp -name core -type f -print0 | xargs -0 /bin/rm -f
      • los nombres que contienen comillas simples o dobles, espacios o nuevas líneas se manejan correctamente
        • -printf0
          • Le dice a find que imprima todos los resultados en std, cada uno separado con el carácter ASCII NUL "\ 000"
      • xargs -0 Le dice a xargs que la entrada se separará con el carácter ASCII NUL "\ 000"
    • find . -type f -exec file '{}' \;
    • find / \( -perm -4000 -fprintf /root/suid.txt '%#m %u %p\n' \) , \ \( -size +100M -fprintf /root/big.txt '%-10s %p\n' \)
    • find $HOME -mtime 0
    • find /sbin /usr/sbin -executable \! -readable -print
    • find . -perm 664
      • find . -perm -664
        • find . -perm /222
    • find . -perm /220 find . -perm /u+w,g+w find . -perm /u=w,g=w
    • find . -perm -220 find . -perm -g+w,u+w
    • find . -perm -444 -perm /222 \! -perm /111 find . -perm -a+r -perm /a+w \! -perm /a+x
    • find -type d -fprint allDirs -o -type f -fprint allFiles
    • sudo find . -name \*.php -type f -exec grep -Hn '$test' {} \;
      • find . -name \*.php -type f -exec grep -Hn '$test' {} \+
        • find . -name \*.php -type f -print0 | xargs -0 -n1 grep -Hn '$test'
          • find . -name \*.php -type f -print0 | xargs -0 grep -Hn '$test'
            • Si no se especifica -n [int], xargs usa el valor predeterminado de -n5000
            • time find . -name \*.php -type f -exec grep -Hn '$test' {} \
              • time: determine tiempo de ejecucion
              • time find . -name \*.php -type f -exec grep -Hn '$test' {} \+
                • time find . -name \*.php -type f -print0 | xargs -0 -n1 grep -Hn '$test'
                  • time find . -name \*.php -type f -print0 | xargs -0 -grep -Hn '$test'
          • -n1 Le dice a xarg que ejecute el comando [cmd] con un solo argumento (en este caso, solo se encuentra un archivo mediante la búsqueda).
    • find . -name \*.log -mtime +30 | xargs -n 500 rm
      • find . -name \*.log -mtime +30 -print0 | xargs -0 -n 500 rm
        • eliminar 1.2 millones de archivos en un directorio de más de 30 días
    • find . -maxdepth 1 -type f -name "*.txt" -size 1205c -print0 | xargs -0 ls -l
      • find . -maxdepth 1 -type f -name "*.txt" -size 1205G -print0 | xargs -0 ls -l