Visit Our UNIX and Linux User Community

find and replace a string in a file without the use of temp file

Thread Tools Search this Thread
Top Forums Shell Programming and Scripting find and replace a string in a file without the use of temp file
# 1  
Old 08-12-2009
find and replace a string in a file without the use of temp file

Hi -

I am looking for a replacing a string in a in multiple *.sql files in directory with a new string without using a temporary file

Normally I can use sed command as below

for W in ls `FILE*.sql`
sed 's/OLD/NEW/g' $W > TEMPFILE.dat
mv TEMPFILE.dat $W

But Here in my scenario I do not want to make use of a temporary file ,rather I would like to directly replace the string in the original files itself.

Please suggest me any command or approach

# 2  
Old 08-12-2009
sed -i 's/OLD/NEW/g' FILE*.sql

# 3  
Old 08-12-2009
Something like this :

perl -i -pe 's/OLD/NEW/ '  File_name.txt

# 4  
Old 08-12-2009
for W in ls `FILE*.sql`
cat $W |sed 's/OLD/NEW/g' >$W

# 5  
Old 08-12-2009
I tried the -i option but getting the below error
sed: Not a recognized flag: i
# 6  
Old 08-12-2009
To keep the forums high quality for all users, please take the time to format your posts correctly.

First of all, use Code Tags when you post any code or data samples so others can easily read your code. You can easily do this by highlighting your code and then clicking on the # in the editing menu. (You can also type code tags [code] and [/code] by hand.)

Second, avoid adding color or different fonts and font size to your posts. Selective use of color to highlight a single word or phrase can be useful at times, but using color, in general, makes the forums harder to read, especially bright colors like red.

Third, be careful when you cut-and-paste, edit any odd characters and make sure all links are working property.

Thank You.

The UNIX and Linux Forums


Thanks to vgersh99 for that example:
printf '1,$ s/OLD/NEW/g\nw! infile\nq!'| ex - infile

# 7  
Old 08-14-2009
Originally Posted by panyam
Something like this :

perl -i -pe 's/OLD/NEW/ '  File_name.txt

Thanks Panyam.It works great.
Could you please explein me how the above command works.
I am new to perl


---------- Post updated at 06:51 AM ---------- Previous update was at 06:45 AM ----------


Thanks to vgersh99 for that example:
printf '1,$ s/OLD/NEW/g\nw! infile\nq!'| ex - infile


Thanks Vgersh.That works great.
Can you please explain me the above code in detail.I have never used such command to find replace a string in a file before


Previous Thread | Next Thread
Test Your Knowledge in Computers #465
Difficulty: Medium
A 2017 security audit of three NTP implementations, conducted on behalf of the Linux Foundation's Core Infrastructure Initiative, suggested that both NTP was less secure than Chrony.
True or False?

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

Find all .sh files in file system and need to replace the string inside .sh files

Hi All, I need to write a script to find all "*.sh" files in /home file system and if any string find "*.sh" files with the name need to replace with I just understood about the find the command to search .sh files. Please help me on this. find / -name... (3 Replies)
Discussion started by: bhas85
3 Replies

2. Shell Programming and Scripting

Replace string of a file with a string of another file for matches using grep,sed,awk

I have a file comp.pkglist which mention package version and release . In 'version change' and 'release change' line there are two versions 'old' and 'new' Version Change: --> Release Change: --> cat comp.pkglist Package list: nss-util-devel-3.28.4-1.el6_9.x86_64 Version Change: 3.28.4 -->... (1 Reply)
Discussion started by: Paras Pandey
1 Replies

3. UNIX for Beginners Questions & Answers

Find and replace a string in a text file

Dear all, I want to find all the "," in my text file and then replace the commas to a tab. I found a script online but I don't know how to modify the script for my case. Any one can help? Thank you. @echo off &setlocal set "search=%1" set "replace=%2" set "textfile=Input.txt" set... (2 Replies)
Discussion started by: forevertl
2 Replies

4. Shell Programming and Scripting

Perl script to read string from file#1 and find/replace in file#2

Hello Forum. I have a file called abc.sed with the following commands; s/1/one/g s/2/two/g ... I also have a second file called abc.dat and would like to substitute all occurrences of "1 with one", "2 with two", etc and create a new file called abc_new.dat sed -f abc.sed abc.dat >... (10 Replies)
Discussion started by: pchang
10 Replies

5. Shell Programming and Scripting

Help with Passing the Output of grep to sed command - to find and replace a string in a file.

I have a file example.txt as follows :SomeTextGoesHere $$TODAY_DT=20140818 $$TODAY_DT=20140818 $$TODAY_DT=20140818I need to automatically update the date (20140818) in the above file, by getting the new date as argument, using a shell script. (It would even be better if I could pass... (5 Replies)
Discussion started by: SriRamKrish
5 Replies

6. Shell Programming and Scripting

Find and replace string based on entries on another file

I have a file1 with different with multiple fields and records File2 has 2 fields. I want to find and replace strings in file1 based on file2 values (I Want an exact match i.e. for example: when searching for DT:3, Substr of DT:34 should not be matched) File2: DT:3 foo_err DT:34 bar_frr... (8 Replies)
Discussion started by: aydj
8 Replies

7. Shell Programming and Scripting

find string and replace with string in other file

Dear all, I need your help, I have file like this: file1:23456 01910964830098775635 34567 01942809546554654323 67589 26546854368698023653 09778 58716868568576876878 08675 86178546154065406546 08573 54165843543054354305 . .file2: 23456 25 34567 26 67589 27 (2 Replies)
Discussion started by: attila
2 Replies

8. Shell Programming and Scripting

replace (sed?) a single line/string in file with multiple lines (string) from another file??

Can someone tell me how I can do this? e.g: Say file1.txt contains: today is monday the 22 of NOVEMBER 2010 and file2.txt contains: the 11th month of How do i replace the word NOVEMBER with (5 Replies)
Discussion started by: tuathan
5 Replies

9. Shell Programming and Scripting

How to find a certain string in a file and replace it with a value from another file using sed/awk?

Hi Everyone, I am new to this forum and new to sed/awk programming too !! I need to find particular string in file1(text file) and replace it with a value from another text file(file2) the file2 has only one line and the value to be replaced with is in the second column. file 1: (assert (=... (21 Replies)
Discussion started by: paramad
21 Replies

10. Shell Programming and Scripting

Find and replace string from file which contains variable and path - SH

e.g. /home/$USER/.config replace it with "" (empty) Is this possible? I think you should play a bit with sharps ## and sed:b: (2 Replies)
Discussion started by: hakermania
2 Replies

Featured Tech Videos