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Sara
Sara

Reputation: 2436

How can I remove lines from .txt files using a loop?

In my current directory I have a couple of .txt files. I want to write a script to search for a string in those .txt files, and delete lines which contains that string. For example, I'd like to delete all lines which have the word "start" in all .txt files in my current directory.

I have written the following code, but I don't know how to continue!

#!bin\bash
files=`find . -maxdepth 1 -name \*.txt`

How should I use "while" to go through each file?

Upvotes: 3

Views: 7092

Answers (4)

M. Zain Aldin
M. Zain Aldin

Reputation: 15

with open(file_listoflinks, 'r+', encoding='utf-8') as f_link:
    lines = f_link.readlines() # read an store all lines into list
    f_link.seek(0) # move file pointer to the beginning of a file
    f_link.truncate() # truncate the file
    # start writing lines except the first line
    # lines[1:] from line 2 to last line
    f_link.writelines(lines[1:])

Upvotes: 0

Todd A. Jacobs
Todd A. Jacobs

Reputation: 84353

Use Globs to Populate Loop Variables

When you use -maxdepth 1 on the current directory, you aren't recursing into subdirectories. If that's the case, there's no need at all to use find just to match files with an extension; you can use shell globs instead to populate your loop constructs. For example:

#!/bin/bash

# Run sed on each file to delete the line.
for file in *txt; do
    sed -i '/text to match/d' "$file"
done

This is simple, and avoids a number of filename-related issues that you may have when passing filename arguments between processes. Keep it simple!

Upvotes: 4

Chirlo
Chirlo

Reputation: 6132

Easy cheasy: sed -i "s/^.*string.*//" *.txt this will remove any line containing 'string' on each .txt file

Upvotes: 3

Ignacio Vazquez-Abrams
Ignacio Vazquez-Abrams

Reputation: 798686

You use it along with read to get each filename in turn, after piping the results of find to it. Then you just pass the filename to sed to delete the lines you're interested in.

Upvotes: 1

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