linux command line and shell scripting bible

Linux Shell reads a lineMethod OneBy specifying IFS--Internal Field Separator , by IFS default , you can set a value in the script IFSDEMO 1$cat t1.txt abcfd $cat test_IFS.sh #! /bin/shIFS="c"for LINE in `cat t1.txt`do echo $LINEdone$sh test_IFS.sh abfdYou need to read a line here just to IFS="\n" set the

Existing file1, file2, file3 three files, the contents are as follows$cat File1f1_1f1_2f1_3$cat File2f2_1f2_2f2_3$cat File3f3_1f3_2f3_3Write a shell script to read these three files line by row#!/bin/bashcat file1 file2 file3 |while read P do echo $p done650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/74/B7/wKioL1YnbFei3OsoAADI9g9zU3A856.jpg "title=" 1111111.jpg "alt=" Wkiol1ynbfei3osoaadi9g9zu3a

Problem descriptionFor Linux systems, many times are used for servers and the like, this time is not open desktop system, so that the command line operation, can effectively save the use of system RAM, so that as many resources as possible for the use of important service. So it is very popular to operate on a Linux system using the command line.Shutdown operatio

the most recent command starting with Blah, such as!ls !blah:p: Print output only, without performing !$: The last parameter of the previous command, with Alt +. Same !$:p: Print out the contents of the!$ !*: All parameters of the previous command !*:p: Print out the contents of the!* ^blah: Delete blah from previous command ^blah^foo: Replace blah in the previous command with Foo ^blah^foo^: Replace all blah in the previous command with Foo Ctrl+p: Previous

Label:1. View data from a shell prompt under MySQL specified database table 2. Delete all the tables under the specified database under MySQL in bulk, Ruiy complete the absolute test---pass the pass for in 'echo' usese;show tables | Mysql-p321 '; Do " drop table SE. $TB " -p321; Done Further complete the statement for, filter out the Tables_in_DBName for in 'echo' usese;show tables | mysql-p321| grep " tables_in "`; Do " drop table SE. $TB "

understanding input and outputREDIRECT Error messages Ls-al badfile 2> test4 redirection errors and data Ls-al test test2 test3 badtest 2> test6 1> #错误输入到test6, normal data is displayed to Test7 test7 test ls-al > test2 #将标准错误和 Standard input is redirected to Test8 Redirecting output in scriptOutput text to standard error echo "This is a error message" GT;AMP;2 can use the EXEC command to tell the shell script to redirect a particular file descriptor

This article is also the seventh chapter of "Learning the bash Shell" 3rd Edition, "Input/Output and Command-Line Processing", four of the Reading Notes. Our goal is to read books thin. We will examine how the Linux system parses bash. Step 1: The command is assigned as a token based on spaces, tabs, NEWLINE,;, (,), Step 2: Check whether the first token has

Environment Variables Section:1. View Global variables: printenv/env2. Displays the value of a single environment variable: Echo as Echo $HOME3. Display all environment variables set for a particular process: set4. Setting global variables: Creating local environment variables--exporting to the global environmentCreate local environment variables (use all lowercase to differentiate from system variables)Test= ' Testing a long string '//environment variable name, equals, value no space betweenExp