The extra command for Unix text processing

Print the lines that are in any of the inputs.

Syntax:

extra <input> ...

Example:

$ extra 1.txt 2.txt
=> lines that are not in 1.txt, but are in 2.txt.

Notes

The order doesn't matter.

In set theory, this command is (A extra B) a.k.a. (B - A).

This command is currently implemented using awk and POSIX.

Related

Related commands for Unix text processing sets:

• union: print lines in (A union B)
• intersect: print lines in (A intersect B)
• except: print lines in (A except B) a.k.a. (A - B)
• extra : print lines in (A extra B) a.k.a. (B - A)

Examples:

$ cat 1.txt
alpha
bravo

$ cat 2.txt
alpha
charlie

$ union 1.txt 2.txt
alpha
bravo
charlie

$ intersect 1.txt 2.txt
alpha

$ except 1.txt 2.txt
bravo

$ extra 1.txt 2.txt
charlie

Tracking

• Program: extra
• Version: 2.0.2
• Created: 2017-01-30
• Updated: 2017-01-30
• License: GPL
• Contact: Joel Parker Henderson (joel@joelparkerhenderson.com)