Linux/Unix:Find and Replace: Difference between revisions

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[[Category:Bash]]
[[Category:Linux/Unix]]


==cat==
==cat==


==head tail==
==head & tail==
 
Show only top or bottom lines from a file
;tail <num> filename
:Show the last <num> lines from filename. 10 is the default
;tail -f filename
:Keep showing all files appended to the file
;head -<num> filename
:Show the first <num> lines from filename. 10 is the default
;head -n -<num> filename
:Show all except the last <num> lines from filename
;tail -n +<num> filename
:Show all lines from line <num> onwards
 
;tail -n +<lineno> filename|head -<num>
:show <num> lines starting at <lineno>


==fold==
==fold==


==strings==
==strings==
;strings filename
:Try to show the file content in printable characters


==more less==
==more less==
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==tr==
==tr==
;tr "[:upper:]" "[:lower:]"
;tr <nowiki>"[:upper:]" "[:lower:]"</nowiki>
;tr "[abc]" "[xyz]"
;tr <nowiki>"[abc]" "[xyz]"</nowiki>
:Transtlate, make all lowercase
:Transtlate, make all lowercase
:replace all a's with y, all b's with y and all c's with z, works from stdin to stdout. All sort of translations can be done
:replace all a's with y, all b's with y and all c's with z, works from stdin to stdout. All sort of translations can be done
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==grep==
==grep==


==sed==
==[[Sed]]==
See the [[Sed]] page.
;s/pattern/newstring/
:In each line replace first occurrence of pattern with newstring. /g at the end replaces all occurrences of pattern.
 
;s/pattern/d
:Delete each line matching pattern.


==awk==
==[[Awk]]==
See the [[Awk]] page


==read==
==read==

Latest revision as of 14:09, 15 November 2022


cat

head & tail

Show only top or bottom lines from a file

tail <num> filename
Show the last <num> lines from filename. 10 is the default
tail -f filename
Keep showing all files appended to the file
head -<num> filename
Show the first <num> lines from filename. 10 is the default
head -n -<num> filename
Show all except the last <num> lines from filename
tail -n +<num> filename
Show all lines from line <num> onwards
tail -n +<lineno> filename|head -<num>
show <num> lines starting at <lineno>

fold

strings

strings filename
Try to show the file content in printable characters

more less

tr

tr "[:upper:]" "[:lower:]"
tr "[abc]" "[xyz]"
Transtlate, make all lowercase
replace all a's with y, all b's with y and all c's with z, works from stdin to stdout. All sort of translations can be done
tr -d <char>
Delete <char> from standard input

grep

Sed

See the Sed page.

s/pattern/newstring/
In each line replace first occurrence of pattern with newstring. /g at the end replaces all occurrences of pattern.
s/pattern/d
Delete each line matching pattern.

Awk

See the Awk page

read