Retrieve only a single line from a file

rose_bud4201 · 06-22-2005, 02:38 PM

I know the line number that I need from a file, and all I need is that line...
I've tried "cat -n $filename | grep ^$linenumber", but cat -n appears to pad each line before it prints the line number, and it pads it with different numbers of spaces depending on the file...so this is out.

Anyone know how to do this?

keefaz · 06-22-2005, 02:52 PM

With sed, to print the 3rd line :

Code:

sed -n 3p $filename

kaz2100 · 06-22-2005, 02:55 PM

Code:

cat -n $filename | grep ^$linenumber | cut -d ' ' -f 2-

Code:

cat  $filename | sed -e $linenumber/P

second one might not be correct, refer "man sed", it's been long since I used sed last time.

rose_bud4201 · 06-22-2005, 03:02 PM

*bows before keefaz*

My day just got a lot happier :-)

I'll have to look up what it is that "cut -d ' ' -f 2-" is doing...I'm not entirely clear on it.

perfect_circle · 06-22-2005, 06:26 PM

this looks relative to what you are asking:
http://www.linuxquestions.org/questi...hreadid=302951

Personally to extract the 50th line of a file I would use this:

Code:

head -50 <filename> | tail -1

but there are faster ways to do that.