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Full Discussion: Question on bash redirection
Top Forums UNIX for Beginners Questions & Answers Question on bash redirection Post 303035996 by bakunin on Wednesday 12th of June 2019 01:36:42 AM
Old 06-12-2019
Quote:
Originally Posted by sand1234
Can I get some explanation around this bash redirection?
Code:
diff <(sort testfile.txt) <(sort testfile2.txt)

This is a so-called "process substitution", where a process (or, rather, its outout) is put into the place of a file. First, there is a diff command:

Code:
diff file1 file2

which would list the differences between these two files. Now, both "file1" and "file2" are substituted by a process:

Code:
<(sort testfile.txt)

So, the file "testfile.txt" is sorted and the result of this sorting (the output of this process) is used as input to the diff command instead of a regular file. Likewise with the second file. This mechanism is called "process substitution".

I hope this helps.

bakunin
This User Gave Thanks to bakunin For This Post:
 

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CUT-DIFF(1)							  Cutter's manual						       CUT-DIFF(1)

NAME
cut-diff - show difference between 2 files with color SYNOPSIS
cut-diff [option ...] file1 file2 DESCRIPTION
cut-diff is a diff command that uses diff feature in Cutter. It shows difference with color. It's recommended that you use a normal diff(1) when you want to use with patch(1) or you don't need color. OPTIONS
--version cut-diff shows its own version and exits. -c [yes|true|no|false|auto], --color=[yes|true|no|false|auto] If 'yes' or 'true' is specified, cut-diff uses colorized output by escape sequence. If 'no' or 'false' is specified, cut-diff never use colorized output. If 'auto' or the option is omitted, cut-diff uses colorized output if available. The default is auto. -u, --unified cut-diff uses unified diff format. --context-lines=LINES Shows diff context around LINES. All lines are shown by default. When unified diff format is used, 3 lines are shown by default. --label=LABEL, -L=LABEL Uses LABEL as a header label. The first--label option value is used as file1's label and the second --label option value is used asfile2's label. Labels are the same as file names by default. EXIT STATUS
The exit status is 0 for success, non-0 otherwise. TODO: 0 for non-difference, 1 for difference and non-0 for errors. EXAMPLE
In the following example, cut-diff shows difference between file1 and file2: % cut-diff file1 file2 In the following example, cut-diff shows difference between file1 and file2 with unified diff format: % cut-diff -u file1 file2 SEE ALSO
diff(1) Cutter February 2011 CUT-DIFF(1)
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