shell if file exist

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>

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

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

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

Shell is like the editor: everyone has their own choice and tries to defend the choice and tell you why it should be used ). Indeed, shell provides different functions, but they all implement the core concept of development decades ago. I used

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

20.5 logical Judgments in shell scripts• format 1:if conditions; Then statement; FiExample: a=5If [$a-gt 3]; then echo OK; Fi[Email protected] shell]# sh If1.shok• format 2:if conditions; Then statement; else statement; FiExample: a=5If [$a-gt 3];

--book author Shenmon reprint please specify the source Content Introduction Objective What is a shell? Our first shell script Run the shell script Summarize Part V Third lesson preview: variable in hand, shell not

Logical judgment in the shell Format 1:if condition; Then statement; FI//If the condition is met, then execute the statement[[email protected] shell]# cat if1.sh #!/bin/basha=5if [ $a -gt 3 ]then echo okfi[[email protected] shell]# sh -x if1.sh +

Shell is like the editor: everyone has their own choice and tries to defend the choice (it also tells you why the choice should be used ). Indeed, s Shell is like the editor: everyone has their own choice and tries to defend the choice (it also