How do I remove a specific pattern from a Unix file?

How do I remove a Unix pattern?

N command reads the next line in the pattern space. d deletes the entire pattern space which contains the current and the next line. Using the substitution command s, we delete from the newline character till the end, which effective deletes the next line after the line containing the pattern Unix.

How do you remove certain lines from UNIX file?

To Remove the lines from the source file itself, use the -i option with sed command. If you dont wish to delete the lines from the original source file you can redirect the output of the sed command to another file.

How do I remove special characters from a Unix file?

Remove CTRL-M characters from a file in UNIX

  1. The easiest way is probably to use the stream editor sed to remove the ^M characters. Type this command: % sed -e “s/^M//” filename > newfilename. …
  2. You can also do it in vi: % vi filename. Inside vi [in ESC mode] type: :%s/^M//g. …
  3. You can also do it inside Emacs.
THIS IS IMPORTANT:  How do I run a file in Unix?

How do I delete a file with a pattern?

The rm command can remove multiple files at once either by passing it more than one file or by using a pattern. In the following example a pattern is used to remove all filenames ending in ‘. txt’. Be careful that no unwanted files are removed using this method.

How do I remove the first character from a Unix file?

You can also use the 0,addr2 address-range to limit replacements to the first substitution, e.g. That will remove the 1st character of the file and the sed expression will be at the end of its range — effectively replacing only the 1st occurrence. To edit the file in place, use the -i option, e.g.

How do I remove the first 100 lines in Unix?

Remove first N lines of a file in place in unix command line

  1. Both sed -i and gawk v4.1 -i -inplace options are basically creating temp file behind the scenes. IMO sed should be the faster than tail and awk . – …
  2. tail is multiple times faster for this task, than sed or awk . (

How do I remove the first 10 lines in Unix?

How it works :

  1. -i option edit the file itself. You could also remove that option and redirect the output to a new file or another command if you want.
  2. 1d deletes the first line ( 1 to only act on the first line, d to delete it)
  3. $d deletes the last line ( $ to only act on the last line, d to delete it)

How do I remove lines from a file?

Use del to delete a line from a file where its position is known {#use-del)

  1. a_file = open(“sample.txt”, “r”) get list of lines.
  2. lines = a_file. readlines()
  3. a_file.
  4. del lines[1] delete lines.
  5. new_file = open(“sample.txt”, “w+”) write to file without line.
  6. for line in lines:
  7. new_file. write(line)
  8. new_file.
THIS IS IMPORTANT:  Quick Answer: How do I change SATA settings in BIOS?

How do I remove the last 10 lines in Unix?

It’s a little roundabout, but I think it’s easy to follow.

  1. Count up the number of lines in the main file.
  2. Subtract the number of lines you want to remove from the count.
  3. Print out the number of lines you want to keep and store in a temp file.
  4. Replace the main file with the temp file.
  5. Remove the temp file.

How do I remove special characters from a file in Linux?

Remove files with names containing strange characters such as spaces, semicolons, and backslashes in Unix

  1. Try the regular rm command and enclose your troublesome filename in quotes. …
  2. You can also try renaming the problem file, using quotes around your original filename, by entering: mv “filename;#” new_filename.

How do I remove special characters from a text file?

Or if you really want to remove the special characters in your file (as you state in the title of your question), you can use iconv -f … -t ascii//TRANSLIT . In this last case, the “special characters” will be approximated by normal ASCII characters.

Operating system reviews