Kenneth at 23:26, 23 November 2022

2022-11-23T23:26:22Z

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== grep ==

Print only matching:
grep -o '[PATTERN]'

Get IP addresses:
ifconfig | grep -o '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}'

IP=`curl -s ip.oeey.com`
echo "$IP" | grep -o '^[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}$'
echo $? # 0 on success, 1 on fail

Ignore fully commented lines:
cat [file] | grep -v "^\s*#" | grep -v "^$"

== OR ==

grep -e pattern1 -e pattern2 filename

grep -E "pattern1|pattern2"

grep "pattern1\|pattern2"

ref: [https://www.thegeekstuff.com/2011/10/grep-or-and-not-operators/]

== Show Non ASCII Characters ==

grep -a --color='auto' -P -n "[\x80-\xFF]" file.xml
grep -a --color='auto' -P -n "[^\x00-\x7F]" file.xml

echo '소녀시대' | grep -P "[\x80-\xFF]"

grep -axv '.*' file.txt # doesn't seem to work on anything

Sample: https://www.w3.org/2001/06/utf-8-wrong/UTF-8-test.html

ref: https://stackoverflow.com/questions/3001177/how-do-i-grep-for-all-non-ascii-characters

== Detect Corrupted Unicode Characters ==

awk '/[^\x00-\x7F]/{ print NR ":", $0 }' file.txt

<pre>
$ awk '/[^\x00-\x7F]/{ print NR ":", $0 }' file
1: Interruptor EC nÃ£o estÃ¡ em DESLOCAR
4: è¾…åŠ©é©¾é©¶å®¤é—¨å…³é—
5: Porte cab. aux. fermÃ©e
7: Ð”Ð²ÐµÑ€ÑŒ Ð°Ð¿Ð¿Ð°Ñ€Ð°Ñ‚Ð½Ð¾Ð¹ ÐºÐ°Ð¼ÐµÑ€Ñ‹ Ð·Ð°ÐºÑ€Ñ‹Ñ‚Ð°
13: é«˜åŽ‹ä¿æŠ¤æ‰‹æŸ„å‘ä¸‹
14: BarriÃ¨re descendue
16: ÐžÐ³Ñ€Ð°Ð½Ð¸Ñ‡. ÐŸÐ»Ð°Ð½ÐºÐ° Ð’Ð’Ðš Ð¾Ð¿ÑƒÑ‰.
19: Barra de separaÃ§Ã£o descida
22: DPæœªå¯åŠ¨
23: Puiss. rÃ©p. non activÃ©e
25: !!! Ð’Ð½ÐµÑˆÐ½ÑÑ Ð¼Ð¾Ñ‰Ð½Ð¾ÑÑ‚ÑŒ Ð½Ðµ Ð²ÐºÐ»ÑŽÑ‡ÐµÐ½Ð°
26: PotÃªncia Dist NÃ£o Ativada
28: PotÃªncia dist nÃ£o activada
31: æœºè½¦æœªç§»åŠ¨
33: Motor no se estÃ¡ moviendo
34: Ð›Ð¾ÐºÐ¾Ð¼Ð¾Ñ‚Ð¸Ð² Ð½ÐµÐ¿Ð¾Ð´Ð²Ð¸Ð¶ÐµÐ½
35: Auto NÃ£o se Movendo
37: A nÃ£o se move
40: æœºè½¦çŠ¶å†µå…è®¸è‡ªåŠ¨åœæœº
41: Conditions auto\npermettent arrÃªt auto
43: Ð£ÑÑ‚Ð°Ð½Ð¾Ð²ÐºÐ¸ Ð»Ð¾ÐºÐ¾Ð¼Ð¾Ñ‚Ð¸Ð²Ð°\nÐŸÑ€ÐµÐ´ÑƒÑÐ¼Ð°Ñ‚Ñ€Ð¸Ð²Ð°ÑŽÑ‚ Ð °Ð²Ñ‚Ð¾Ð¼Ð°Ñ‚Ð¸Ñ‡ÐµÑÐºÑƒÑŽ Ð¾ÑÑ‚Ð°Ð½Ð¾Ð²ÐºÑƒ
44: CondiÃ§Ãµes da moto\nPermitem Auto Parada
</pre>

Ref: https://stackoverflow.com/questions/30738924/detecting-corrupt-characters-in-utf-8-encoded-text-file

--

Assuming you have your locale set to UTF-8 (see locale output), this works well to recognize invalid UTF-8 sequences:

grep -axv '.*' file.txt

Ref: https://stackoverflow.com/questions/29465612/how-to-detect-invalid-utf8-unicode-binary-in-a-text-file

== keywords ==

[[Category:Linux]]

Linux/grep - Revision history

Kenneth at 23:26, 23 November 2022