Hari's Technical Space

This hack explains how to use sed substitute command “s”. The `s’ command is probably the most important in `sed’ and has a lot of different options. The `s’ command attempts to match the pattern space against the supplied REGEXP; if the match is successful, then that portion of the pattern space which was matched is replaced with REPLACEMENT. Syntax:

You can use one of the 5 methods explained in this hack to execute a Linux command, or shell script in the background.   Method 1. Use & You can execute a command (or shell script) as a background job by appending an ampersand to the command as shown below.   $ ./my-shell-script.sh &   Method 2. Nohup After you

Ac command will display the statistics about the user’s connect time.   Connect time for the current logged in user With the option –d, it will break down the output for the individual days. In this example, I’ve been logged in to the system for more than 6 hours today. On Dec 1st, I was logged in for about 1

Diff command compares two different files and reports the difference. The output of the diff command is very cryptic and not straight forward to read. Syntax: diff [options] file1 file2   What was modified in my new file when compare to my old file?   The option -w in the diff command will ignore the white space while performing the

Stat command can be used either to check the status/properties of a single file or the filesystem. Display statistics of a file or directory.   $ stat /etc/my.cnf File: `/etc/my.cnf’ Size: 346 Blocks: 16 IO Block: 4096 regular file Device: 801h/2049d Inode: 279856 Links: 1 Access: (0644/-rw-r–r–) Uid: (0/root) Gid: (0/root) Access: 2009-01-01 02:58:30.000000000 -0800 Modify: 2006-06-01 20:42:27.000000000 -0700 Change: