- Test if the specified variable has a [n]on-empty value: [[ -n $variable ]] - Test if the specified variable has an empty value: [[ -z $variable ]] - Test if the specified [f]ile exists: [[ -f path/to/file ]] - Test if the specified [d]irectory exists: [[ -d path/...
-S file exists and is a socket. -t file descriptor number fildes is open and associated with a terminal device. -u file exists and has its setuid(2) bit set. -w file exists and is writable by the current process. -x file exists and is executable by the current process. -z string...
检查一个文件是否存在,而且是普通文件:$test –ffile.txt;echo$? 检查一个文件是否存在,而且是目录文件:$test –d myfiles;echo$? 检查一个文件是否存在,而且是软连接:$test –L a.out;echo$? 检查一个文件是否可读:$test –rfile.txt;echo$? 检查一个文件是否可写:$test –wfile.txt;echo$? 检查一...
-S file exists and is a socket. -t file descriptor number fildes is open and associated with a terminal device. -u file exists and has its setuid(2) bit set. -w file exists and is writable by the current process. -x file exists and is executable by the current process. -z string...
-x:Executable...可执行 ... 条件判断的表达式: [ expression ] 注意[] 最左和左右需要空格,这里linux把表达式当成命令来判断 ` expression ` 同样需要注意空格,这里linux把表达式当成关键字来判断,至于两者区别,暂时存疑 test expression 命令间的逻辑
File Test Operators Here, we will list some helping testing operators for permissions, size, date, file type, or existence in the bash script. Operators Explanation -e To test if a file exists. -f To test if a given file is a regular file. -d To test if the file is a directory. ...
Version 3.7.2 2005/11/16 作者:Mendel Cooper mail:thegrendel@theriver.com 这本书假定你没有任何脚本或一般程序的编程知识,但是如果你有相关的知识,那么你将很容易 达到中高级的水平...all the while sneaking in little snippets of UNIX? wisdom and lor... ...
Size is > 0 bytes [[ -f FILE ]] # File [[ -x FILE ]] # Executable [[ FILE1 -nt FILE2 ]] # 1 is more recent than 2 [[ FILE1 -ot FILE2 ]] # 2 is more recent than 1 [[ FILE1 -ef FILE2 ]] # Same files if [[ -e "file.txt" ]]; then echo "file exists" fi...
echo "file is not executable" # will this if test work? case $1 "--extract") if [ -e $2 ] && [ tar -tzf $2 >/dev/null ]; then echo "file exists and is tar archive" else echo "file either does not exists or it is not .tar arcive" fi ;; esac 上面的代码不起作用,它...
This checks whether a file is executable (by the current user) or not. If a file is executable, then it returns 0, else it returns 1: [ test -x filename ] && echo executable || echo non-executable You can use other file permissions like r and w in the same fashion. Other common...