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Comment: Yes, remove the cut example, especially if people are going to use --gnu-only-long-options in their examples. :-/
← Revision 11 as of 2008-11-22 14:09:45 → ⇥
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Another approach, using ["AWK"]: Another approach, using [[AWK]]:

How can I print the n'th line of a file?

The dirty (but not quick) way would be: 

    sed -n ${n}p "$file"

but this reads the whole input file, even if you only wanted the third line.

This one avoids that problem: 

    sed -n "$n{p;q;}" "$file"

At line $n the command "p" is run, printing it, with a "q" afterwards: quit the program.

Another way, more obvious to some, is to grab the last line from a listing of the first n lines: 

   head -n $n $file | tail -n 1

Another approach, using AWK: 

   awk "NR==$n{print;exit}" file

If you want more than one line, it's pretty easy to adapt any of the previous methods: 

   x=3 y=4;
   sed -n "$x,${y}p;${y}q;" "$file"                # Print lines $x to $y; quit after $y.
   head -n $y "$file" | tail -n $(($y - $x + 1))   # Same
   awk "NR>=$x{print} NR==$y{exit}" "$file"        # Same

BashFAQ/011 (last edited 2020-05-07 08:35:17 by intranet)