shell scripts

[Alice_4]

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...

[harry d brown jr]

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

[Jean-Louis Phelix · Accepted solution]

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

[Alice_4]

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...