overwrite specific lines in a file


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting overwrite specific lines in a file
# 1  
Old 05-09-2008
overwrite specific lines in a file

Hi all,

I am trying to overwrite some lines of a very big file.
I know the number of the line but I don't know how to point the cursor on its beginning. there is an option to notice the offset in lines?

thanks!
# 2  
Old 05-09-2008
Are you in an editor?
for vi <esc>20204G takes you to line 20204

Or do you want to replace line #x with text using another tool?
# 3  
Old 05-09-2008
no, I want to do it in a boot script.

I want to do it by commands lines.
# 4  
Old 05-09-2008
For large files sed it's the best tool.
# 5  
Old 05-10-2008
The ed(1) utility is typically used for such tasks.
# 6  
Old 05-10-2008
Ok I have used it, but I think that my manner is not really elegant.

Do you know how to (by sed)...

overwrite a line which actually you only know how it begins but not how finishes?

I want to change a settings file... so I want to do something like that.

sed '49s/HorizSync[...]/HorizSync 30.0 - 83.0/g' xorg.conf

where [...] are characters which I don't know.

Thanks a lot!!
# 7  
Old 05-10-2008
Code:
 sed 's/^HorizSync.*/HorizSync 30.0 - 83.0/g' file

Regards
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Overwrite specific column in xml file with the specific column from adjacent line

I have an xml file dumped from rrd file, that I want to "patch" so the xml file doesn't contain any blank hole in the resulting graph of the rrd file. Here is the file. <!-- 2015-10-12 14:00:00 WIB / 1444633200 --> <row><v> 4.0419731265e+07 </v><v> 4.5045912770e+06... (2 Replies)
Discussion started by: rk4k
2 Replies

2. UNIX for Dummies Questions & Answers

Add strings from one file at the end of specific lines in text file

Hello All, this is my first post so I don't know if I am doing this right. I would like to append entries from a series of strings (contained in a text file) consecutively at the end of specifically labeled lines in another file. As an example: - the file that contains the values to be... (3 Replies)
Discussion started by: gus74
3 Replies

3. UNIX for Dummies Questions & Answers

Quick UNIX command to display specific lines in the middle of a file from/to specific word

This could be a really dummy question. I have a log text file. What unix command to extract line from specific string to another specific string. Is it something similar to?: more +/"string" file_name Thanks (4 Replies)
Discussion started by: aku
4 Replies

4. Shell Programming and Scripting

awk search/replace specific field, using variables for regexp & subsitution then overwrite file

Hello, I'm trying the solve the following problem. I have a file which I intend to use as a csv called master.csv The columns are separated by commas. I want to change the text on a specific row in either column 3,4,5 or 6 from xxx to yyy depending upon if column 1 matches a specified pattern.... (3 Replies)
Discussion started by: cyphex
3 Replies

5. Shell Programming and Scripting

Extracting specific lines of data from a file and related lines of data based on a grep value range?

Hi, I have one file, say file 1, that has data like below where 19900107 is the date, 19900107 12 144 129 0.7380047 19900108 12 168 129 0.3149017 19900109 12 192 129 3.2766666E-02 ... (3 Replies)
Discussion started by: Wynner
3 Replies

6. Shell Programming and Scripting

Substitute specific lines with lines from another file

Hello All, I am new to this forum. I am currently facing a problem in manipulating files. I have two files called old-matter and new-matter # cat old-matter abc: this, is a, sample, entry byi: white board, is white in color rtz: black, board is black qty: i tried, a lot asd: no... (1 Reply)
Discussion started by: rahmathulla
1 Replies

7. UNIX Desktop Questions & Answers

shell overwrite lines in a file

Hello, I have an external file (file.txt). This shall be a kind of a config file for my shell script. I get the line numbers as to a corresponding entry by grep. Now I would like to substitute the corresponding line from the shell script back to the file and exactly on the same line number. ... (4 Replies)
Discussion started by: ACTGADE
4 Replies

8. UNIX for Dummies Questions & Answers

how to display specific lines of a specific file

are there any basic commands that can display lines 99 - 101 of the /etc/passwd file? I'm thinking use of head and tail, but I forget what numbers to use and where to put /etc/passwd in the command. (2 Replies)
Discussion started by: raidkridley
2 Replies

9. Shell Programming and Scripting

remove specific lines from a file

Hi there I have a file with a variable amount of rows but the 45th, 46th and 47th charachter of each line is the status field which is a three digit code ie 001, 002, 003 etc. My question is this..I need to strip all the records/lines with 002's out of the file completely and put them into... (14 Replies)
Discussion started by: hcclnoodles
14 Replies

10. UNIX for Dummies Questions & Answers

How do you specific lines in a file?

I'm looking to show specific lines (eg. 20 through 40) of a series of files in the directory. How do I do this? (2 Replies)
Discussion started by: hedgehog001
2 Replies
Login or Register to Ask a Question