Shell special symbol cut,sort_wc_uniq,tee_tr_split, Shell special symbol

Special symbols

• * Any character
• ？ Any one character
• Comment characters

  Indicates that the order does not take effect, and explains

• \ de-Semantic characters

• | Pipe breaks, several commands related to pipelines
  • Cut command: Intercept string

CAT/ETC/PASSWD |cut-d ":"-F

-D delimiter

-F Specify segment number

-c Specifies the number of characters, the use of the time can not use the-D,-F.

• Sort: Sorting commands, by default in Asma order

-N is numerically sorted and the default letters and special symbols are considered to be 0

-R reverse sequence, with Asma in turn

-T separator character. -kn1/-kn1,n2

• Wc-l: Statistics Row Count command

[[email protected] ~]# wc -l 1.txt 25 1.txt

WC-M: Number of statistics characters

[[email protected] ~]# wc -m 1.txt 487 1.txt

Wc-w: Statistical words, separated by blank characters

• Uniq need to be adjacent to repeat the word to remove, so generally first sort after the removal of duplicate sort 2.txt |uniq-c

  -C Count of duplicate rows

Tee and > similar

Visual redirection

[[email protected] ~]# sort 1.txt > a.txt[[email protected] ~]# cat a.txt >.@ "111n1.txt* 2222333222444222555222aaaa2.txt3333334444444adm:x:3:4:adm:/var/adm:/sbin/nologinbin:x:1:1:bin:/bin:/sbin/ Nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinhalt:x:7:0:halt:/sbin:/sbin/haltlp:x:4:7:lp:/var/spool/lpd:/sbin /NOLOGINLS: Unable to access asffsfs.txt: No file or directory mail:x:8:12:mail:/var/spool/mail:/sbin/nologinoperator:x:11:0:operator:/ root:/sbin/nologiroot:x:0:0:root:/root:/bin/bashshutdown:x:6:0:shutdown:/sbin:/sbin/shutdownsync:x:5:0:sync:/ Sbin:/bin/sync[[email protected] ~]# sort 1.txt |tee a.txt>.@ 111n1.txt* 2222333222444222555222aaaa2.txt3333334444444adm:x:3:4:adm:/var/adm:/sbin/nologinbin:x:1:1:bin:/bin:/sbin/ Nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinhalt:x:7:0:halt:/sbin:/sbin/haltlp:x:4:7:lp:/var/spool/lpd:/sbin /NOLOGINLS: Unable to access asffsfs.txt: No file or directory mail:x:8:12:mail:/var/spool/mail:/sbin/nologinoperator:x:11:0:operator:/ Root:/sbin/nologiroot:x:0:0:root:/root:/bin/bashshutdown: x:6:0:shutdown:/sbin:/sbin/shutdownsync:x:5:0:sync:/sbin:/bin/sync[[email protected] ~]#  

• |tee-a Visual Append redirect

• TR Replacement Character

[[email protected] ~]# echo "aminglinux" |tr ‘a‘ ‘A‘Aminglinux

[[email protected] ~]# echo "aminglinux" |tr ‘[anx]‘ ‘[ANX]‘AmiNgliNuX

[[email protected] ~]# echo "aminglinux" |tr ‘[a-z]‘ ‘[A-Z]‘AMINGLINUX

Split cut

• -b Specifies the split size: split-b 100M bigfile filename (does not write unit default display is bytes)
• -l Specifies the number of split file lines: split-l bigfile filename

Shell Special Symbols

• $ variable prefix,!$ combination, regular inside means end of line
• ; Multiple commands written to one line, separated by semicolons
• ~ User home directory, followed by regular expression to indicate match
• & put the command behind the command and throw it backstage.
• > >> 2> 2>> &>
• [] One of the specified characters
• || and &&, used between commands
  • || or the meaning of
  • &&
• ||

  if | | The previous command prompt succeeded, | | The subsequent command will not execute, if the previous command execution is unsuccessful, the | | The following command.

• &&

  If the previous command executes successfully, the subsequent command is executed, and if the previous command is wrong, the following command is not executed.

Shell special symbol cut,sort_wc_uniq,tee_tr_split, Shell special symbol