UNIX for Dummies Questions & Answers

Hi,
I have a problem where I need to append few spaces(say 10 spaces) for each line in a file whose length is say(100 chars) and others leave as it is.

I tried to find the length of each line and then if the length is say 100 chars then tried to write those lines into another file and use a sed to append spaces to the new file.However the data in each line can have multiple spaces in between and I am losing those extra spaces while copying the line into another file.

For eg:
while read line
a=${#line}
do
if ((a==100))
echo $line >> tempfile
fi
done<sourcefile

The problem with the same code is its suppressing multiple spaces into one space if the line has multiple spaces.

Please help

Try this one in awk, it appends 10 spaces to lines with a length of 100 chars without changing other lines:

Code:

awk 'length==100{print $0 "          ";next}1' file

Regards

Thanks a ton!

It helped..
Thank you once again!

Hi ,

i need awk command for which it appends 100 blank spaces for Header (starts wirh H..) and Trailer (starts with T..) in a file.

HODACC(need to add 100 blank spaces here)
D0000...
D0000.....
..
..
T000013(need to add 100 blank spaces here)

thanks...

it sounds like you want a variable length record file turned into a fixed width record file.

Here's a general awk script you might be able to tweak:

awk '{ printf( "%-106.106s\n", $0 ); }' file_in > file_out

You can add search strings so it's more selective, if you need to.
But it won't hurt on records that are already the right length.

thanks for reply.....

I am new to unix....
I require to append 100 spaces(fillers) to header(first line) and 100 space to trailer(last line).
the data in the middle not to be changed.

i do not want variable length record file turned into a fixed width record file. i just need to append 100 fillers in the first line and 100 fillers in last line

sample file:

HODA(need to add 100 fillers(spaces) here)
D0000000000000000000000000000000000
D0000000000000000000000000000000000
T000012(need to add 100 fillers(spaces) here)

Try something like this:

Code:

awk -v n=`wc -l < file` '
BEGIN{s=sprintf("%-100s", "")}
NR==1{$0=$0 s)}
NR==n{$0=$0 s)}
1' file

Regards