??????????????????????Linux????????????????????????о????????????Щ????????????????????????????????Щ???????????????Щ???????????????????????????????????????
????1??ls????
?????????????????μ?????б????????????ls??????????????????
????-l ??ó??б???
????-h ?????С?????????????
????-t ?????????????μ?????
?????????????????????????????μ?????У?
????????1?? ls -l | grep '^d'
????????2?? ls -l | awk '/^d/'
????2??grep????
?????????????????????????????????????grep????????漸???????
????-w ???????????????????????????????????????abc?????????abcd
????-i ?????д??Сд
????-n ????????????????????к?
????-v ???????????????????
????-f ?????????????????
?????????????
????grep ^$ file ??????file?е????????
????grep -v '^$' file ??????file?е?????????
????grep '[^^$]' file ??????file?е?????????
????grep -vf t2 t1 ???t1?и?t2?????????????????????t1????????t2??????
???????????[^$]????????У???????^?????????????
????3????????????? sort vs uniq
????sort ?????????????????????
????-t ?????????????
????-n ???????????б????????????????
????-r ????????
????-u ???????????
????-k ??????????????????????1??
????+?????????????-????????????????? sort +0 -2 +3???????0?????????????2???????????3??????
????uniq ???????????????????????????У???????sort????????uniq??
????-d ???????????ε???
????-c ??????????г???????
????sort -u ??uniq?????????uniq????????????????У???sort -u????????????????????????У????磬
????#????file1?е?????
????hello world
????Good morning
????Good morning
????hello world
????#???sort -u < file1???????????￡?
????hello world
????Good morning
???????uniq < file1???????????￡?
????hello world
????Good morning
????hello world
????4??tr????
??????????????Щ??????????滻????????tr???????ú???á?
???????磬???μ?tr??????????????????????????????????????
????tr 'A-Z' 'a-z' < file ??????????д???????Сд?????
????tr -s ' ' ' ' < file ????????????滻????????-s????????????????滻??????????
????tr -s ' ' < file ???????
????tr -d '[0-9]' < file ???????????-d?????????????????