TEXT_PROCESSING(oh)		     LOCAL		   TEXT_PROCESSING(oh)

text processing - tools

sed(oh)	  : text stream editor, commonly used for substitution.
cut(oh)	  : split string.
tr(oh)	  : translate characters.
paste(oh) : join files/lines.
awk	  : pattern processing language.

sed
     replace old with new	   : s/old/new/
     replace all occurrences	   : s/old/new/g
     replace the second occurrence : s/l/p/2

   Examples
     $ echo "hello" | sed "s/l/p/"
     heplo
     $ echo "hello" | sed "s/l/p/g"
     heppo
     $ echo "hello" | sed "s/l/p/2"
     helpo

cut
     -d	  | delimeter
     -c	  | split by character count
     -d	  | split by character (specify delimeter)
     -f	  | specify field count. Use n,-n,n-
		-f 2, gets 2nd field; -f -2, gets up to the 2nd field; -f 2-,
		gets from the 2nd field to the end

     $ echo "a b c" | cut -d " " -f 2
     b
     $ echo "a b c" | cut -d " " -f 2-
     b c
     $ echo hello | cut -c 2
     e

tr
     $ echo "hello" | tr "l" "m"
     hemmo

   control chacters
     echo "hello" | tr 'e' '\n'
     h
     llo
     echo 'hello' | tr 'l' '\t'
     he	     o

   character range
     echo 'hello' | tr 'h-l' 'a-d'
     aeddo

   Character classes
     echo '1.hello\n2.goodbye' | tr '[:digit:]' 'a-c'
     b.hello
     c.goodbye

paste
     Requires a file on OpenBSD, cat be a pipe redirection on Slackware.

   OpenBSD
     $ cat test.log
     1
     2
     3
     $ paste -s -d "+" test.log
     1+2+3

   Slackware
     cat test.log | paste -s -d +
     1+2+3

head
     head     : Get first 10 lines of file : head FILENAME
     head -15 : Get first 15 lines of file : head -15 FILENAME

tail
     tail     : Get last 10 lines of file	      : tail FILENAME
     tail -15 : Get last 15 lines of file	      : tail -15 FILENAME
     tail -f  : Get latest lines of file continuously : tail -f FILENAME

grep
     Get lines matching pattern		 : grep PATTERN FILE(S)
     Get lines not matching pattern	 : grep -v PATTERN FILE(S)
     Get file names not matching pattern : grep -L PATTERN FILE(S)
     Get line numbers matching pattern	 : grep -n PATTERN FILE(S)
     Case-insensitive search for pattern : grep -i PATTERN FILE(S)
     Recursive search			 : grep -R PATTERN DIRECTORY

TODO
     - Translate to Spanish.
     - review and improve if needed.

SEE ALSO
     openbsd(oh), slackware(oh)
     OpenBSD manpages: paste(1), tr(1), head(1), tail(1), grep(1)

HISTORY
     2026-06-02 : Fixed name: text_manipulation > text_processing.
     2025-10-03 : Created

AUTHORS
     ohazot(oh) | about(oh) | ohazot.com: https://ohazot.com
     <admin@ohazot.com>

				  2026-06-02		   TEXT_PROCESSING(oh)