head cut outs

Text processing cat more less head tail sort uniq grep cut jion sed awk################################################cat:concatenate files and print on the standard output display the contents of the file to the normal outputs (display)-E: Displays the last character at the end-N: Show line numbering[Email protected] ~]# cat-n/etc/shells1/bin/sh2/bin/bash3/sbin/nologin4/bin/dash5/bin/tcsh6/bin/csh[Email p

==================head==================The first 10 lines of the default output file contentsNAME-Output the first part of the filesSynopsis (outline, abstract)-head [option] ... [File] ...Parameters-N Specify row-C--bytes-V Show file name-------------------------------#显示前5行Head-n 5/etc/inittabHead-5/etc/inittab #只需要掌握这条命令即可-------------------------------#显示前5个

specifies the delimiter,-K is sorted with a position of key:Sort-t:-K 3/tmp/passwd, which means that all rows are sorted by the third column ":" As the delimiter;Uniq: Displays or ignores duplicate rows, noting that only adjacent and identical rows are considered duplicates, such as the contents of the Sort.test file:[Email protected] ~]# cat/tmp/sort.test 111324567324890890567ABCUsing the Uniq command, you can see that the original line "890" is ignored and shown:[Email protected] ~]# UNIQ/TMP

(1) Effect(2) Source code download (material replacement)http://download.csdn.net/detail/wsb200514/8183437(3) Summary-All of these can be packaged to develop their category based on UIImage.--graphical context, with main operations such as opening uigraphicsbeginimagecontextwithoptions, getting uigraphicsgetcurrentcontext and closing Uigraphicsendpdfcontext , there will be a turn off.--Other pictures and text, is directly with drawinrect painting to the context, only the screenshot is different,

format: "tail [options] [file]"View the following 20 lines of the text file:Tail - Filename Tail parameters Parameters Role -N 10 Show back 10 rows -F Refresh the displayed content continuously 5. The TR command is used to convert characters in a text file in the format: "tr[original character [target character]"Cat tr. Tex | TR [A-z] [A-z]6. The OD command is used for viewing files in special formats. Format as