topic Re: shell scripts in Operating System - HP-UX

shell scripts

Alice_4 — Thu, 28 Nov 2002 15:57:40 GMT

i'm a beginner for sed n awk,so i can't reali understand what those means:

sed 's/'"$1"'/&/g
2,$ d' |
awk ' {
right += length($0);
print right, $0;
}'

help from anyone is highly appreciated...
thank you...

Re: shell scripts

harry d brown jr — Thu, 28 Nov 2002 16:01:20 GMT

Where did you get the code? Do you have any idea what the input is?

It's usually necessary to see the entire picture, not just what's in the box.

live free or die
harry

Re: shell scripts

Jean-Louis Phelix — Thu, 28 Nov 2002 16:19:14 GMT

hi,

I try to work without context ...

I can't understand the meaning of first sed line, because basically it's supposed to substitute something by ... the same thing ! The & char is usually used with something else, for example :

sed 's/xxx/< & >/g'

would have changed all occurences of xxx in < xxx > (multiple changes on same lines by adding a final g, else sed go to next line after first replacement.

So, first instruction doesn't seem very useful, try with or without it, it's the same ...

then '2,$ d' would suppress all lines after line 1, so 'line' or 'head -1' would have done it quicker.

then right += length($0); would add length of input record to variable 'right', but in your case, with 1 record only, '=' would have been enough ...

And it finally prints the lenght of the record and the record itself.

If you cat a file into this script, same result would be obtained by :

VAR=$(line)
echo ${#VAR} $VAR

Regards

Re: shell scripts

Alice_4 — Fri, 29 Nov 2002 04:52:13 GMT

hi harry,
i get this code from the net when i'm searching for some notes on sed codes. i can't understand so i post it up.
anyway thanks for your help.
i really have no idea about this code...