一般用法
grep -R '時間' *
- -r, –recursive like –directories=recurse
- -R, –dereference-recursive likewise, but follow all symlinks
- –include=FILE_PATTERN search only files that match FILE_PATTERN
- –exclude=FILE_PATTERN skip files and directories matching FILE_PATTERN
- –exclude-from=FILE skip files matching any file pattern from FILE
- –exclude-dir=PATTERN directories that match PATTERN will be skipped.
- –exclude-dir={dir1,dir2,dir3} directories that match PATTERN will be skipped.
- -i, –ignore-case ignore case distinctions
- -P, –perl-regexp
- -o, –only-matching
grep ^d：過濾出資料夾
OR
沒有任何 option, 必須使用 \| 來分隔 pattern :
grep 'pattern1\|pattern2' filename
grep 'Tech\|Sales' employee.txt
使用 option -E (extended regexp), 使用 | 分隔 pattern :
grep -E 'pattern1|pattern2' filename
grep -E 'Tech|Sales' employee.txt
使用 egrep 指令, 相當於使用 grep -E :
egrep 'pattern1|pattern2' filename
egrep 'Tech|Sales' employee.txt
使用 option -e, 但 pattern 必須分開寫
grep -e pattern1 -e pattern2 filename
grep -e Tech -e Sales employee.txt
AND
AND 在 grep 沒有操作符, 可以使用 -E 達成 :
grep -E 'pattern1.*pattern2' filename
grep -E 'pattern1.*pattern2|pattern2.*pattern1' filename
grep -E 'Dev.*Tech' employee.txt
grep -E 'Manager.*Sales|Sales.*Manager' employee.txt
使用 linux 原生指令 | 來達成 :
grep -E 'pattern1' filename | grep -E 'pattern2'
grep Manager employee.txt | grep Sales
NOT
使用 -v (invert match) 達成, 它會顯示除了符合 pattern 以外的搜尋結果
grep -v 'pattern1' filename
grep -v Sales employee.txt
egrep 'Manager|Developer' employee.txt | grep -v Sales
Others
只過濾出符合的部份
echo 'hello world' | grep -oP 'hello \K(world)'
ref :
http://www.thegeekstuff.com/2011/10/grep-or-and-not-operators/