.Dd 2026-06-02
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.Dt TEXT_PROCESSING oh
.Nm text processing
.Nd tools
.Tg index
.obc paste_
.It Li Xr sed oh Ta : text stream editor, commonly used for substitution.
.It Li Xr cut oh Ta : split string.
.It Li Xr tr oh Ta : translate characters.
.It Li Xr paste oh Ta : join files/lines.
.It Li Xr awk Ta : pattern processing language.
.El
.Sh sed
.obc replace_the_second_occurre
.It replace old with new Ta : Li  s/old/new/
.It replace all occurrences Ta : Li s/old/new/g
.It replace the second occurrence Ta : Li s/l/p/2
.El
.Ss Examples
.obd $ echo \&"hello\&" | sed \&"s/l/p/\&"
heplo
$ echo "hello" | sed "s/l/p/g"
heppo
$ echo "hello" | sed "s/l/p/2"
helpo
.Ed
.Sh cut
.obc _
.It -d Ta | delimeter
.It -c Ta | split by character count
.It -d Ta | split by character (specify delimeter)
.It -f Ta | specify field count. Use n,-n,n-
.D1 -f 2, gets 2nd field; -f -2, gets up to the 2nd field; -f 2-, gets from the 2nd field to the end
.El
.Bd -literal -compact
$ 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
.Ed
.Sh tr
.Bd -literal -compact
$ echo "hello" | tr "l" "m"
hemmo
.Ed
.Ss control chacters
.obd echo \&"hello\&" | tr 'e' '\en'
h
llo
.Ed
.Ss
.obd echo 'hello' | tr 'l' '\et'
he	o
.Ed
.Ss character range
.obd echo 'hello' | tr 'h-l' 'a-d'
aeddo
.Ed
.Ss Character classes
.obd echo '1.hello\en2.goodbye' | tr '[:digit:]' 'a-c'
b.hello
c.goodbye
.Ed
.Sh paste
Requires a file on OpenBSD, cat be a pipe redirection on Slackware.
.Ss OpenBSD
.Bd -literal -compact
$ cat test.log
1
2
3
$ paste -s -d "+" test.log
1+2+3
.Ed
.Ss Slackware
.obd cat test.log | paste -s -d "+"
1+2+3
.Ed
.Sh head
.obc head_ get_first_10_line_of_file
.It head Ta : Get first 10 lines of file Ta : Li head FILENAME
.It head -15 Ta : Get first 15 lines of file Ta : Li head -15 FILENAME
.El
.Sh tail
.obc tail_ get_last_10_lines_of_file_continuou_
.It tail Ta : Get last 10 lines of file Ta : Li tail FILENAME
.It tail -15 Ta : Get last 15 lines of file Ta : Li tail -15 FILENAME
.It tail -f Ta : Get latest lines of file continuously Ta : Li  tail -f FILENAME
.El
.Sh grep
.obc case_insensitive_search_for_patt
.It Get lines matching pattern Ta : Li grep PATTERN FILE(S)
.It Get lines not matching pattern Ta : Li grep -v PATTERN FILE(S)
.It Get file names not matching pattern Ta : Li grep -L PATTERN FILE(S)
.It Get line numbers matching pattern Ta : Li grep -n PATTERN FILE(S)
.It Case-insensitive search for pattern Ta : Li grep -i PATTERN FILE(S)
.It Recursive search Ta : Li grep -R PATTERN DIRECTORY
.El
.Sh TODO
.obc
.It - Translate to Spanish.
.It - review and improve if needed.
.El
.Sh SEE ALSO
.obc
.It
.Xr openbsd oh ,
.Xr slackware oh
.It OpenBSD manpages:
.Xr paste 1 ,
.Xr tr 1 ,
.Xr head 1 ,
.Xr tail 1 ,
.Xr grep 1
.El
.Sh HISTORY
.obc _______
.It 2026-06-02 Ta : Fixed name: text_manipulation > text_processing. 
.It 2025-10-03 Ta : Created
.El
.Sh AUTHORS
.An -nosplit
.Xr ohazot oh | 
.Xr about oh |
.Lk https://ohazot.com ohazot.com
.Aq Mt admin@ohazot.com