-s FILE FILE exists and has a size greater than zero 如果文件存在且文件大小大于零,则返回真 -e FILE FILE exists 如果文件存在,则返回真 在shell中通过test指令测试文件是否为空的示例脚本如下: #! /bin/sh if test -s file.txt; then echo "hi" else echo "empty" fi 在shell中,test指令还有另外...
ubuntu linux 에서 shell script 를 사용하다보면 파일의 유무를 확인해야 하는 경우가 자주 있습니다. 이럴 때 사용할 수 있는 방법은 조건문에서 특별한 옵션을 사용하는 것 입니다. 기...
If-statement-Bash-Script-Example if-else Statement 除了普通的 if 语句之外，我们还可以用 else 块扩...
In a script, you would typically use it in an if statement. To negate and check if the folder or file doesnotexist, use either "!" or "-not", and remember to enclose the Test-Path statement in parentheses. Also remember that if the path or folder name contains a space, you need to...
if grep $testuser /etc/passwd #查询 then #状态码0,执行 echo "The user $testuser exists on this system." else #否则,执行 echo "The user $testuser does not exist on this system." if ls -d /home/$testuser/ #在进入一个if语句 ...
#if[ -x test9.sh]thenecho"You can run the script:"elseecho"Sorry,You are unable to execute the script"]fi 执行该脚本,结果如下: 2.8 检查所属关系 -O比较可以测试出你是否是文件的属主 #!/bin/bash #checkfileownership #if[ -O /etc/passwd]thenecho"You are the owner of the /etc/passw...
Can be used to extend oroverride settings in the global configuration script. ~/.bash_login If ~/.bash_profile is not found, bash attempts toread this script. ~/.profile If neither ~/.bash_profile nor ~/.bash_loginis found, bash attempts to read this file. This is thedefault in ...
If File exists then copy it script powershell If is not recognized as the name of a cmdlet? if not contains If statement based on day of the week evaluating despite being false If Test-Connection do these action else exit. If variable is null or empty skip in script If with multiple c...
本章还要求大家能够在Shell脚本中以多种方式接收用户输入的信息,能够对输入值进行文件、数字、字符串的判断比较。在熟练使用“与、或、非”三种逻辑操作符的基础上,大家还要充分学习if、for、while、case条件测试语句,并通过10多个实战脚本的实操练习,达到在工作中灵活运用的水准。
--file=ARCHIVE 使用归档文件或 ARCHIVE 设备 --force-local 即使归档文件存在副本还是把它认为是本地归档 -F, --info-script=名称, --new-volume-script=名称 在每卷磁带最后运行脚本(隐含 -M) -L, --tape-length=NUMBER 写入 NUMBER × 1024 字节后更换磁带 -M, --multi-volume 创建/列出/解压多卷归...