Visit Our UNIX and Linux User Community


Urgent help required in deleting a line without opening a file usinga shell script


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Urgent help required in deleting a line without opening a file usinga shell script
# 1  
Old 07-20-2006
Urgent help required in deleting a line without opening a file usinga shell script

Hi,

I need a help in deleting a line matching a particular pattern in a file using shell script without opening the file. The file is a .c/.cpp file. Is it possible?

Thanks
# 2  
Old 07-20-2006
Quote:
Originally Posted by naan
Hi,

I need a help in deleting a line matching a particular pattern in a file using shell script without opening the file. The file is a .c/.cpp file. Is it possible?

Thanks
Hi naan, you can overright the file.
eg. I have a file name.cpp & i wanna delete line with a text "test file". then do it like this

cat name.cpp | grep -v "test file" > name.cpp

"grep -v "test file" will display the name.cpp without line containing words "test file" & " >name.cpp" will overright the previous file

Regds,
Girish
# 3  
Old 07-20-2006
Bug delete line with Overrighting the file

Hi naan, you can delet th eline by overrighting the file.
eg. I have a file name.cpp & i wanna delete line containing words "test file". then do it like this

cat name.cpp | grep -v "test file" > name.cpp

"grep -v "test file" will display the name.cpp without line co Smilie ntaining words "test file" & " >name.cpp" will overright the previous file

Regds,
Girish
# 4  
Old 07-20-2006
Quote:
Originally Posted by girish.karulkar
cat name.cpp | grep -v "test file" > name.cpp
That command will wipe out the complete file.

You should be doing
Code:
grep -v "test file" name.cpp > name.cpp.new
mv name.cpp.new name.cpp

# 5  
Old 07-20-2006
Quote:
Originally Posted by vino
That command will wipe out the complete file.

You should be doing
Code:
grep -v "test file" name.cpp > name.cpp.new
mv name.cpp.new name.cpp

Yes. I do agree !
# 6  
Old 07-20-2006
Additional help

Thanks a lot for the input...So can we use the same solution while writing a batch DOS program to delete a particular line from a set of files within a folder so that it recursively goes and delete the line in all the files. Smilie
# 7  
Old 07-20-2006
I think by Dos batch program you mean a shell script, if that is the case then try this:
Code:
#! /bin/ksh

for i in *.cpp;
do
grep -v "test file" $i > $i.new
mv $i.new $i
done

Regards,
Tayyab

Previous Thread | Next Thread
Test Your Knowledge in Computers #213
Difficulty: Medium
OSPF-TE is an extension to OSPF extending the expressivity to allow for traffic engineering and use on non-IP networks.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

URGENT Reading a file and assessing the syntax shell script URGENT

I am trying to write a shell script which takes an input file as an arguement in the terminal e.g. bash shellscriptname.sh input.txt. I would like for the file to be read line by line each time checking if the .txt file contains certain words or letters(validating the syntax). If the line being... (1 Reply)
Discussion started by: Gurdza32
1 Replies

2. Shell Programming and Scripting

Bash script to read a file from particular line till required line and process

Hi All, Am trying to write wrapper shell/bash script on a utility tool for which i need to pass 2 files as arugment to execute utility tool. Wraper script am trying is to do with above metion 2 files. utility tool accepts : a. userinfo file : which contains username b. item file : which... (2 Replies)
Discussion started by: Optimus81
2 Replies

3. Shell Programming and Scripting

deleting lines in a file that match a pattern without opening it

In Unix, how do I delete lines in a file that match a particular pattern without opening it. File contents are foo line1 misc whatever foo line 2 i want to delete all lines that have the pattern "foo" without opening the file. File should eventually contain misc whatever (1 Reply)
Discussion started by: osbourneric
1 Replies

4. Shell Programming and Scripting

Help with opening another file from within a shell script

Hi, I am trying to open a file that I have created from withn a shell script and cannot seem to get it working. Does anyone have any ideas? Thanks. (2 Replies)
Discussion started by: tdsrogers
2 Replies

5. Shell Programming and Scripting

Deleting a line from a flatfile using Shell Script

Hi All, Can Anyone please tell me,how can I delete a line from a file. I am reading the file line by line using whil loop and validating each line..Suppose in the middle i found a particular line is invalid,i need to delete that particular line. Can anyone please help. Thanks in advance,... (14 Replies)
Discussion started by: dinesh1985
14 Replies

6. Shell Programming and Scripting

Urgent!! : How to read very long line using shell script

I have to fix files with only one huge line. Basically this line contains huge number of records may be in thousands of fix length. Suppose if we consider the length of one record as 100 bytes and if we have 50 such record. Then the file will have only one line with 100*50 bytes. I want to... (3 Replies)
Discussion started by: hrvispute
3 Replies

7. Shell Programming and Scripting

Shell Script for deleting the first line in a file

Hi, Could any one please post the shell script for deleting the first line in a file? (3 Replies)
Discussion started by: badrimohanty
3 Replies

8. Shell Programming and Scripting

Shell script interview question...help required urgent!!!

hi i have cancelled my previous post (2 Replies)
Discussion started by: choco4202002
2 Replies

9. Shell Programming and Scripting

Getting Following problem when opening shell script (Very Urgent)

Hi All, Actually when i am trying to open my shell script file 1.sh then i am getting the following error. > vi 1.sh "/var/tmp/ExdNaarK" No space left on device Can anybody tell me that how to rectify it. It is very urgent. Because i am not able to do any work due to the above error. ... (1 Reply)
Discussion started by: sunitachoudhury
1 Replies

10. Shell Programming and Scripting

Very Urgent help required in Shell Program

How do I Ftp, and rename multiple files in one unix script. I have to send it with .tmp extension , then rename it to .txt after FTP is done . I need to do a Mass rename of more than 1 file in a shell script , Urgent help required. (1 Reply)
Discussion started by: Suppandi
1 Replies

Featured Tech Videos