Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers scripting...
# 1  
Old 05-11-2001
Hi everyone
This is something I have always managed to get around, rather laboriously and I'm sure it can be done...

I need to search for a line in a file which matches a pattern, and replace that line with another line - and I need to place this into a script so that it is automated. Interactively this takes 1 minute using vi, but I need to put this into a script.

Does anyone have an idea how to do this?

# 2  
Old 05-14-2001
This can be done with PERL is one line.
# 3  
Old 05-14-2001
How about using sed?

cat file|sed 's/old pattern/new pattern/g' >new_file

You can use sed to do a lot of editing "automatically"
strip off leading blanks on a line: 's/^ *//g'
strip off trailing blanks on a line: 's/ *$//g'
delete blank lines : '/^$/d'

you can use regular expressions as well as specific strings.
# 4  
Old 05-15-2001
I think we mistaken alwayslearningunix's actual problem. What kornshellmaven provide is to change the "searching pattern" with "newpattern" throughout the document. but what alw* need is to find the specific pattern in a line, if it exists in that line then replace entire line with a new line(not just the "searching pattern") Right alw*?. I am also curious to know how to do that. Smilie

I could accomplish this with a perl script. but not a one liner Smilie

PS: kornshellmaven you don't need to use "cat" there(recalls Pxt's statement). sed 's/old pattern/new pattern/g' file >new_file

# 5  
Old 05-15-2001
Here's a perl one-liner:

perl -n -i.bak -e 'if (/pattern/) { print "new text\n"; } else { print; }' inputfile

This will edit the file named "inputfile" in place, and create a backup (unmodified) called inputfile.bak.
Also note that it will modify _every_ line that contains the pattern. You can do the first match only by adding a little extra logic.

# 6  
Old 05-15-2001
Computer cool

Thanks PxT that is exactly what I needed, yes mib you understood my problem perfectly, sorry if I wasnt clear.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Web Development

Perl scripting or shell scripting?

i am going to study any one of the scripting languages mentioned above(shell 0r perl scripting) . Which is having more scope for a fresher? (1 Reply)
Discussion started by: Anna Hussie
1 Replies

2. What is on Your Mind?

Shell Scripting vs Perl scripting

Gents, I have been working in a Solaris/Unix environment for about 9 months. I took some linux classses online before getting the job. But, I am not very good at scripting. I want to learn how to script. Do you think that I should start with Shell scripting or Perl? I wanted to continue with... (2 Replies)
Discussion started by: Pouchie1
2 Replies

3. Android

Android Scripting Environment: Shell Scripting and Android

I just upgraded to Android 2.2 from 2.1. The GPS issue that was troublesome in 2.1 seems to have been fixed. Some of web browsing seems faster, but it could just be my connection is better today ;) Flash works in some browsers but not very good and it is too slow for Flash apps designed for... (0 Replies)
Discussion started by: Neo
0 Replies

4. What is on Your Mind?

Shell scripting vs Perl scripting

Hi all, I would like to start developping some good scripting skills. Do you think it would be best to start with shell scripting or Perl? I already got a fundation, really basics, in perl. but I am wondering what would be best to be good at first. Can you please help me determine which one to... (14 Replies)
Discussion started by: Pouchie1
14 Replies

5. Shell Programming and Scripting

Call Shell scripting from Perl Scripting.

Hi How to call a shell scripting through a Perl scripting? Actually I need some value from Shell scripting and passes in the Perl scripting. So how can i do this? (2 Replies)
Discussion started by: anupdas
2 Replies

6. UNIX for Dummies Questions & Answers

Scripting Help

Hello all. Like Ive stated before, I am new to world of Unix. I was given the tast to create a script that will concatenate 20 files into one file. I know that the cat command is to be used but I am looking for something to get started on. Again, basically I need to wrtie a script that whill... (3 Replies)
Discussion started by: ndoggy020
3 Replies

7. UNIX for Advanced & Expert Users

Need help on scripting

in unix bc command is used as calculator and also for conversion, i want to convert 5f to decimal. but bc dont consider 5f as hex value it considers 5F as hex value. I get 5f from other iteration so i cant change that f to there any way to convert 5f to decimal ot 5f to 5F :rolleyes: (2 Replies)
Discussion started by: abhinandantn
2 Replies

8. Shell Programming and Scripting

difference between AIX shell scripting and Unix shell scripting.

please give the difference between AIX shell scripting and Unix shell scripting. (2 Replies)
Discussion started by: haroonec
2 Replies

9. Shell Programming and Scripting

scripting guru's pls help me with scripting on AIX

can someone pls help me with the script for a files coming from one system to a particular directory and i want to write a script to move those files to another directory on different system by renaming the files... pls someone help me on this... thanking in anticipation.... (1 Reply)
Discussion started by: thatiprashant
1 Replies

10. AIX

New to scripting

We have a scripting requirement, Background: On a particular path, we compress a load of log files into tar.gz. This is done on an hourly basis throughout the day and it produces files of the following format, 2005-08-05-00-021031.tar.gz as an example. This is done by a script. We need: ... (2 Replies)
Discussion started by: rajesh_149
2 Replies
Login or Register to Ask a Question