topic Shell script: put some text in the first line in Operating System - HP-UX

Shell script: put some text in the first line

Sharvil Desai — Tue, 25 Mar 2003 15:51:04 GMT

Can anyone please tell me what is the best way to add some text to the first line of a file that already exists and has lots of lines? Thank you!

Re: Shell script: put some text in the first line

Pete Randall — Tue, 25 Mar 2003 15:54:53 GMT

There's most likely a better way but this would certainly work:

echo "text" > file.new
cat file >> file.new
mv file.new file

Pete

Re: Shell script: put some text in the first line

Sharvil Desai — Tue, 25 Mar 2003 16:05:27 GMT

That would work, but I am hoping that someone can think of a better way. If noone can come up with a way then I will gladly accept your answer and assign points. Thank you.

Re: Shell script: put some text in the first line

Sharvil Desai — Tue, 25 Mar 2003 16:05:47 GMT

That would work, but I am hoping that someone can think of a better way. If noone can come up with a better way then I will gladly accept your answer and assign points. Thank you.

Re: Shell script: put some text in the first line

Hai Nguyen_1 — Tue, 25 Mar 2003 16:25:46 GMT

Sharvil,

Try this:

# echo "new first line text here" | cat - yourfile | tee yourfile

Hai

Re: Shell script: put some text in the first line

Hai Nguyen_1 — Tue, 25 Mar 2003 16:29:32 GMT

Sharvil,

if you want to suppress the ouptput from the above command, then try this:

# echo "new first line text here" | cat - yourfile | tee yourfile >/dev/null

Hai

Re: Shell script: put some text in the first line

Sharvil Desai — Tue, 25 Mar 2003 16:39:19 GMT

Thank you both!
I like Hai Nguyen's answer.
Everyone gets points!

Re: Shell script: put some text in the first line

James R. Ferguson — Tue, 25 Mar 2003 16:40:32 GMT

Hi:

If you like:

# awk 'BEGIN{print "INSERTED_TEXT!"};{print $0}' filename > filename.new
# mv filename.new filename

Regards!

...JRF...

Re: Shell script: put some text in the first line

Chris Vail — Tue, 25 Mar 2003 16:45:24 GMT

Just use vi, or your favorite text editor.
If you're not familiar with vi, here's a quick primer:
vi filename
O (thats capital "O", not zero) to "open" the first line.
Type your text.
:wq (thats the key, followed by the colon, then the w (write) then q (quit). You're done.

Chris

Re: Shell script: put some text in the first line

Curtis Larson_2 — Tue, 25 Mar 2003 16:54:42 GMT

it does depend on where you want to add your text, beginning, end, somewhere in the middle.

you can use sed, awk, ex. to do this.

file.tmp
mv file.tmp file
use a for appending text
i for insert text at the begining
s for subtitution, or changes somewhere in the middle

Re: Shell script: put some text in the first line

Curtis Larson_2 — Tue, 25 Mar 2003 17:12:04 GMT

using awk
< file | awk ' {
if ( NR == 1 ) {
printf("%s",$0);
print " your text";}
else print $0;
}' > file.tmp
mv file.tmp file

that will append to the first line or changing the print statements above will insert

printf("%s","your text ");
print $0;

and of course, awk has several method for adding text somewhere in the middle