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Top Forums Shell Programming and Scripting How to select lines randomly without replacement in UNIX? Post 302981468 by sajmar on Tuesday 13th of September 2016 01:49:39 PM
Old 09-13-2016
Thank you Corona688 for your suggestion. I only present the small example. In my case, I want to randomly choose 5000 lines out of 15000 lines. what should I do for this situation?
 

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LOOK(1) 						    BSD General Commands Manual 						   LOOK(1)

NAME
look -- display lines beginning with a given string SYNOPSIS
look [-df] [-t termchar] string [file ...] DESCRIPTION
The look utility displays any lines in file which contain string as a prefix. As look performs a binary search, the lines in file must be sorted. If file is not specified, the file /usr/share/dict/words is used, only alphanumeric characters are compared and the case of alphabetic char- acters is ignored. Options: -d Dictionary character set and order, i.e. only alphanumeric characters are compared. -f Ignore the case of alphabetic characters. -t Specify a string termination character, i.e. only the characters in string up to and including the first occurrence of termchar are compared. The look utility exits 0 if one or more lines were found and displayed, 1 if no lines were found, and >1 if an error occurred. FILES
/usr/share/dict/words the dictionary SEE ALSO
grep(1), sort(1) COMPATIBILITY
The original manual page stated that tabs and blank characters participated in comparisons when the -d option was specified. This was incor- rect and the current man page matches the historic implementation. HISTORY
A look utility appeared in Version 7 AT&T UNIX. BSD
June 14, 1993 BSD
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