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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:
RavinderSingh13
 

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LEARN ABOUT SUNOS

bzcmp

BZDIFF(1)						      General Commands Manual							 BZDIFF(1)

NAME

       bzcmp, bzdiff - compare bzip2 compressed files

SYNOPSIS

       bzcmp [ cmp_options ] file1 [ file2 ]
       bzdiff [ diff_options ] file1 [ file2 ]

DESCRIPTION

       Bzcmp  and  bzdiff  are used to invoke the cmp or the diff program on bzip2 compressed files.  All options specified are passed directly to
       cmp or diff.  If only 1 file is specified, then the files compared are file1 and an uncompressed file1.bz2.  If two  files  are	specified,
       then they are uncompressed if necessary and fed to cmp or diff.	The exit status from cmp or diff is preserved.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +--------------------+-----------------+
       |  ATTRIBUTE TYPE    | ATTRIBUTE VALUE |
       +--------------------+-----------------+
       |Availability	    | SUNWbzip	      |
       +--------------------+-----------------+
       |Interface Stability | External	      |
       +--------------------+-----------------+
SEE ALSO

       cmp(1), diff(1), bzmore(1), bzless(1), bzgrep(1), bzip2(1)

BUGS

       Messages from the cmp or diff programs refer to temporary filenames instead of those specified.

																	 BZDIFF(1)
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