ls command is one of the most frequently used command in Linux. I believe ls command is the first command you may use when you get into the command prompt of Linux Box.
1. List Files using ls with no option
ls with no option list files and directories in bare format where we won’t be able to view details like file types, size, modified date and time, permission and links etc.
# ls 0001.pcap Desktop Downloads index.html install.log.syslog Pictures Templates anaconda-ks.cfg Documents fbcmd_update.php install.log Music Public Videos
2 List Files With option –l
Here, ls -l (-l is character not one) shows file or directory, size, modified date and time, file or folder name and owner of file and its permission.
# ls -l total 176 -rw-r--r--. 1 root root 683 Aug 19 09:59 0001.pcap -rw-------. 1 root root 1586 Jul 31 02:17 anaconda-ks.cfg drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Desktop drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Documents drwxr-xr-x. 4 root root 4096 Aug 16 02:55 Downloads -rw-r--r--. 1 root root 21262 Aug 12 12:42 fbcmd_update.php -rw-r--r--. 1 root root 46701 Jul 31 09:58 index.html -rw-r--r--. 1 root root 48867 Jul 31 02:17 install.log -rw-r--r--. 1 root root 11439 Jul 31 02:13 install.log.syslog drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Music drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Pictures drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Public drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Templates drwxr-xr-x. 2 root root 4096 Jul 31 02:48 Videos
3. View Hidden Files
List all files including hidden file starting with ‘.‘.
# ls -a . .bashrc Documents .gconfd install.log .nautilus .pulse-cookie .. .cache Downloads .gnome2 install.log.syslog .netstat.swp .recently-used.xbel 0001.pcap .config .elinks .gnome2_private .kde .opera .spice-vdagent anaconda-ks.cfg .cshrc .esd_auth .gtk-bookmarks .libreoffice Pictures .tcshrc .bash_history .dbus .fbcmd .gvfs .local .pki Templates .bash_logout Desktop fbcmd_update.php .ICEauthority .mozilla Public Videos .bash_profile .digrc .gconf index.html Music .pulse .wireshark
4. List Files with Human Readable Format with option -lh
With combination of -lh option, shows sizes in human readable format.
# ls -lh total 176K -rw-r--r--. 1 root root 683 Aug 19 09:59 0001.pcap -rw-------. 1 root root 1.6K Jul 31 02:17 anaconda-ks.cfg drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Desktop drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Documents drwxr-xr-x. 4 root root 4.0K Aug 16 02:55 Downloads -rw-r--r--. 1 root root 21K Aug 12 12:42 fbcmd_update.php -rw-r--r--. 1 root root 46K Jul 31 09:58 index.html -rw-r--r--. 1 root root 48K Jul 31 02:17 install.log -rw-r--r--. 1 root root 12K Jul 31 02:13 install.log.syslog drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Music drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Pictures drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Public drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Templates drwxr-xr-x. 2 root root 4.0K Jul 31 02:48 Videos
5. Display Inode number of File or Directory
We can see some number printed before file / directory name. With -i options list file / directory with inode number.
# ls -i 20112 0001.pcap 23610 Documents 23793 index.html 23611 Music 23597 Templates 23564 anaconda-ks.cfg 23595 Downloads 22 install.log 23612 Pictures 23613 Videos 23594 Desktop 23585 fbcmd_update.php 35 install.log.syslog 23601 Public
6. List Files and Directories with ‘/’ Character at the end
Using -F option with ls command, will add the ‘/’ Character at the end each directory.
# ls -F 0001.pcap Desktop/ Downloads/ index.html install.log.syslog Pictures/ Templates/ anaconda-ks.cfg Documents/ fbcmd_update.php install.log Music/ Public/ Videos/
7.List Files in Reverse Order
# ls -r Videos Public Music install.log fbcmd_update.php Documents anaconda-ks.cfg Templates Pictures install.log.syslog index.html Downloads Desktop 0001.pcap
Hope this blog will be helpful for your troubleshooting and handling the server