abc : The string is not empty 文件测试运算符 实例: #!/bin/bash file="/home/shiyanlou/test.sh" if [ -r $file ] then echo "The file is readable" else echo "The file is not readable" fi if [ -e $file ] then echo "File exists" else echo "File not exists" fi 结果 The file ...
让我们设置一个变量并在test.sh脚本中打印它。bash -posix test.sh #bash: test.sh: command not found . test.sh #bash: .: test.sh: file not found . ./test.sh #hello world PID:23493 ParentPID:19245 ./test.sh #hello world PID:23539 ParentPID:23493 bash test.sh #hello world PID:23540...
echo "$a : The string is not empty" else echo "$a : The string is empty" fi 1. 2. 3. 4. 5. 6. 7. 8. 文件比较运算符 如下例: #!/bin/bash file="/test.sh" # 由于没有给出条件,所以返回true if [ ! ] then echo "File exists" else echo "File not exists" fi 1. 2. 3...
[student@studentvm1 testdir]$ File="TestFile1" ; touch $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ; fi TestFile1 does not exist or is empty. 向文件添加一些内容,然后再测试一次: [student@studentvm1 ...
file $ type -t if keyword 上面例子中,bash是文件,if是关键词。 快捷键 Bash 提供很多快捷键,可以大大方便操作。下面是一些最常用的快捷键,完整的介绍参见《行操作》一章。 Ctrl + L:清除屏幕并将当前行移到页面顶部。 Ctrl + C:中止当前正在执行的命令。
echo'~/ is a directory'elseecho'~/ is not a directory'fi -f即判断是否为file, -d即判断是否为directory, 输出结果: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 +'['-f/Users/yjmyzz/.bash_profile']'+echo'~/.bash_profile is a file'~/.bash_profile is a file+printf'\n'+'['...
Open up you favorite text editor and a create file called hello_world.sh. Insert the following lines to a file: NOTE:Every bash shell script in this tutorial starts withshebang:"#!"which is not read as a comment. First line is also a place where you put your interpreter which is in...
例3:判断文件是否存在,若存在,则输入“ok”;若不存在,则输入“file not exist”。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 if[-f aaa.txt];then echo"ok"elseecho"file not exist"fi 例4:输入当前文件夹的一级子目录中文件名字
A FILE argument that does not exist is created empty, unless -c or -h is supplied. A FILE argument string of - is handled specially and causes touch to change the times of the file associated with standard output. Mandatory arguments to long options are mandatory for short options too. ...
aws_profile_config_add_if_missing.sh - reads AWS profile config blocks from stdin and appends them to the ~/.aws/config file if the profile section is not found aws_profile_generate_direnvs.sh - generates subdirectories containing the config.ini and .envrc for every AWS profile found in ...