?????????????????“shell???????”????????????????????bash??ksh??sh???????????????linux/unix??????????????????????????????????????????????λ???????棨??????windows????linux??????ν????????????????????????????簴????б????????????????????????????????/?????????????????????????????????????????????μ?????mp3?????????????????????????Щ?????ü??????????????????????shell?????
?????Щ??????????pascal??foxpro??C??java????????????????б??????????????????????????????????????????
???????????Щ??????????php??javascript??visualbasic?????????????????????????????????????????????????????????г???
????shell???????????????????????????????????????????????????????????????????????????д????
????Linux??????????е?shell?????????????bash???????????????????????????????????????????bash shell????????????????????????????й????????????????????ksh??????.profile?????Щ?????????????Щ“???”??????????????????????
???????????????Щ???????????????????????????????????????ж?ɡ?????????????????bash????????????????????У???????CentOS 6.6??bash-4.1.2???????????????汾?????????汾??
????Shell?????
????shell???????????????????????????????????????????????????μ???Щ???????????????????????????????????????????д????????????????????????????????????????????????????д???????????????????????????????????????????????????????????????????????????????“?????????”??????????Щ?????????????????????????Щ??????????????“?????????”?????????????????????????????????????????????????????Σ??????????????????????????????????????Щ???????????????????????????????????????з????????????????????“??????”???????????????????????????——????????“???????”?????????????е????????“???????”??????????
???????????——?????linux????д?Щ????——???????“???????”??bash??????????????????????bash shell who am i????????????ɡ?
????root@localhost ~]
????# who am i                                <--- ????????????? bash shell ?
????root     pts/0        2015-04-22 20:17 (192.168.1.123)     <--- bash shell??????????????
?????????????????Щbash????????????
????[root@localhost ~]
????# blablabla           <--- ??????????????????????
????-bash: blablabla: command not found     <--- bash??????????????????
????“:”?????????????????????????????????????Щ???е?????????????????????????LCTT ????????????????
???????????stdin?? – 0
????????????stdout?? – 1
???????????stderr?? – 2
???????????????????????????????Щ??——?????????η????????????????????????“>”???????????????
????[root@localhost ~]
????# blablabla 1> output.txt
????-bash: blablabla: command not found
??????????У????????????????1??stdout???????output.txt??????????????????????????????????????????cat????????????￡?
????[root@localhost ~]
????# cat output.txt
????[root@localhost ~]
????#
???????????????????e?????????????????????2??stderr????
????[root@localhost ~]
????# blablabla 2> error.txt
????[root@localhost ~]
????#
?????e?????????????????????????????????????
????[root@localhost ~]
????# cat error.txt
????-bash: blablabla: command not found
????[root@localhost ~]
????#
??????????????????????????????????????errors.txt??????????
????????????????????stdout ?? stderr????????????????????????????????????????
????command 1>out.txt 2>err.txt
?????????????????????????“1”?????????????stdout???????
????command >out.txt 2>err.txt
?????e??????????????Щ“????”??????????rm?????file1??folder1???????
????[root@localhost ~]
????# rm -vf folder1 file1 > out.txt 2>err.txt
?????????????????????????
????[root@localhost ~]
????# cat out.txt
????removed `file1'
????[root@localhost ~]
????# cat err.txt
????rm: cannot remove `folder1': Is a directory
????[root@localhost ~]
????#
??????????????????????????????????????????????????????????????????????????????????????Щ??????????????????????????顣????????????????????????????????????????
????command >>out_err.txt 2>>out_err.txt
?????????????????“>>”?????“>”???????????????????????????????????
????????????????????????????????
????command >out_err.txt 2>&1
????????????????°ɡ????????????????????????out_err.txt????????????????????1????????????????????????????????????????????????????????
????[root@localhost ~]
????# rm -fv folder2 file2 >out_err.txt 2>&1
????[root@localhost ~]
????# cat out_err.txt
????rm: cannot remove `folder2': Is a directory
????removed `file2'
????[root@localhost ~]
????#
??????????Щ??????????????????????????????rm?????????folder2????????????????????linux???-r????????rm???????????У????????file2???????????rm??-v?????飩??????????rm??????????????????????????????С?