Sysadmin [Howtoforge.com] Linux Commands - Overview and Examples

Linux SSH command line overview and examples Linux Commands - Overview and Examples

Even I learnt some new commands i.e. expand and diff3 !

diff3 compare 3 text files 1.txt, 2.txt, 3.txt contents

Code (Text):

cat 1.txt
1
2
3

Code (Text):

cat 2.txt
4
5
6

Code (Text):

cat 3.txt
7
8
9

Code (Text):

diff3 1.txt 2.txt 3.txt
====
1:1,3c
  1
  2
  3
2:1,3c
  4
  5
  6
3:1,3c
  7
  8
  9

Code (Text):

diff3 --help
Usage: diff3 [OPTION]... MYFILE OLDFILE YOURFILE
Compare three files line by line.

Mandatory arguments to long options are mandatory for short options too.
  -A, --show-all              output all changes, bracketing conflicts

  -e, --ed                    output ed script incorporating changes
                                from OLDFILE to YOURFILE into MYFILE
  -E, --show-overlap          like -e, but bracket conflicts
  -3, --easy-only             like -e, but incorporate only nonoverlapping changes
  -x, --overlap-only          like -e, but incorporate only overlapping changes
  -X                          like -x, but bracket conflicts
  -i                          append 'w' and 'q' commands to ed scripts

  -m, --merge                 output actual merged file, according to
                                -A if no other options are given

  -a, --text                  treat all files as text
      --strip-trailing-cr     strip trailing carriage return on input
  -T, --initial-tab           make tabs line up by prepending a tab
      --diff-program=PROGRAM  use PROGRAM to compare files
  -L, --label=LABEL           use LABEL instead of file name
                                (can be repeated up to three times)

      --help                  display this help and exit
  -v, --version               output version information and exit

The default output format is a somewhat human-readable representation of
the changes.

The -e, -E, -x, -X (and corresponding long) options cause an ed script
to be output instead of the default.

Finally, the -m (--merge) option causes diff3 to do the merge internally
and output the actual merged file.  For unusual input, this is more
robust than using ed.

If a FILE is '-', read standard input.
Exit status is 0 if successful, 1 if conflicts, 2 if trouble.

Report bugs to: bug-diffutils@gnu.org
GNU diffutils home page: <http://www.gnu.org/software/diffutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>

 

grep is a common one How to perform pattern search in files using Grep

 

Folks should definitely bookmark and read this linked guide if they want to be more familiar with SSH commands

@sepulchre