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Top Forums Shell Programming and Scripting Use sed to print first n lines and last n lines of an output. Post 302838971 by Jotne on Wednesday 31st of July 2013 03:18:06 AM
Old 07-31-2013
Just for the fun of it, using awk
Code:
awk '{a[NR]=$0} NR<=n {print} END{for (i=NR-n+1;i<=NR;i++) print a[i]}' n=3 file

This prints the first 3 and last 3 records of file

Or if you like it to the output
cat file | awk '{a[NR]=$0} NR<=n {print} END{for (i=NR-n+1;i<=NR;i++) print a[i]}' n=3
This User Gave Thanks to Jotne For This Post:
 

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colcrt(1)						      General Commands Manual							 colcrt(1)

Name
       colcrt - filter nroff output for CRT previewing

Syntax
       colcrt [-] [-2] [file...]

Description
       The  command provides virtual half-line and reverse line feed sequences for terminals without such capability, and on which overstriking is
       destructive.  Half-line characters and underlining (changed to dashing `-') are placed on new lines in between the normal output lines.

Options
       -  Suppresses all underlining.  It is especially useful for previewing allboxed tables from

       -2 Causes half-lines to be printed, double spacing the output.  Normally, a minimal space output format is used which will  suppress  empty
	  lines.   The	program  never	suppresses  two  consecutive empty lines, however.  The -2 option is useful for sending output to the line
	  printer when the output contains superscripts and subscripts which would otherwise be invisible.

Examples
       A typical use of would be:
       tbl exum2.n | nroff -ms | colcrt - | more

Restrictions
       Can't back up more than 102 lines.

       General overstriking is lost; as a special case `|' overstruck with `-' or underline becomes `+'.

       Lines are trimmed to 132 characters.

See Also
       col(1), more(1), nroff(1), ul(1)

																	 colcrt(1)
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