shell if file exists

1) Unix command: Although any Unix command can be used in shell scripts, some more common commands are used. These commands are usually used for file and text operations. Common command syntax and functions: Echo"Some text": print the text on

Logical judgments in shell scripts Format 1:if condition; Then statement; Fi (Common) #以命令的方式表达[[email protected] ~]# for i in `seq 1 5`; do echo $i; done12345[[email protected] ~]# for i in `seq 1 5`> do> echo $i>

Use the Shell to judge #!/bin/sh mypath= "/var/log/httpd/" myfile= "/var/log/httpd/access.log" #-x parameter determines whether the $mypath exists and has executable permissions if [!-X "$myPath"]; Then mkdir "$myPath" FI # Here's the-D

Use shell script to monitor whether a process exists without a startup instance, first on the code dry: #!/bin/sh ps-fe|grep processstring |grep-v grep if [$-ne 0] then echo "START process ..." elseecho "runing ..." fi

Shell basic syntax Basic shell Syntax:Like advanced programming languages, shell also provides instructions and functions for using variables.For shell, the value of all variables is a string, and the shell program uses $ VaRReference the value

I. Logical judgments in shell scriptsIn the shell script, many will logically judge, judge a certain value, judge a file, or a directory, we do some action against the result of the judgment, if there is no judgment, there is no way to do some

Using a shell to determine whether a device node exists, such as inserting a 4G Modem Sierra module into a Linux system, generates a series of TTY devices, typically with a command to send and receive at. For example, a device node is a/DEV/TTYUSB2

#!/bin/shPs-fe|grep processstring |grep-v grepIf [$?-ne 0]Thenecho "START process ..."Elseecho "Runing ..."Fi#####Processstring represents a process feature string that can be queried for a unique process's characteristic string0 indicates the

Implement code One, #!/bin/sh # to determine if a file exists # link:www.jb51.net # date:2013/2/28 mypath= '/var/log/httpd/ ' myfile= ' Var/log/httpd/access.log " # Here's the-x parameter to determine if $mypath exists and has executable

1. What is a shell script?It is a scripting language, not a programming language.You can use some logical judgments, loops, and other syntax.You can customize the sub-function, which is a collection of system commands.Shell scripts enable automated