shell script language

ztdep · 10-27-2006, 05:18 AM

Hi:
Would you like to provide me some good free references on the linux shell script language.
I encounter some problem when i want to find a variable value from a file and then modify its value.
for example, there is sentence says in the file a.dat

$veleciy=777*0.02542

now , i need to modify 777 to 600. how to do this.

Regards

pwc101 · 10-27-2006, 05:29 AM

Code:

set veleciy=`echo $veleciy | tr "777" "600"`

that'll change the 777 value in the variable veleciy to 600.

There's probably a more elegant way though...

edit: I haven't tested this.

spirit receiver · 10-27-2006, 05:50 AM

Quote:

Originally Posted by pwc101

I haven't tested this.

No doubt about that

To find each line containing "$veleciy=" and replace each occurrence of "777" with "600" in all those lines, you can use

Code:

sed -i.bak '/\$veleciy=/{s/777/600/g}' filename

This will make a backup of the original file.

pwc101 · 10-27-2006, 05:53 AM

it's been a long morning

nayyares · 10-27-2006, 10:13 AM

Hi,
Amazing when i tried this string at google:

shell scripting, pdf

Fredde87 · 10-27-2006, 10:57 AM

Quote:

Originally Posted by nayyares

Hi,
Amazing when i tried this string at google:

shell scripting, pdf

What a coincident, I just typed morron and found a picture of you with a link to this thread.

johnson_steve · 10-27-2006, 12:07 PM

check out:

http://tldp.org/LDP/abs/html/