if(!...PathFileExists(_T(“d:\\test”))) return NULL; 也可用CFileFinder查找文件是否存在。...PathFileExists可查看目录和文件。 1.6K20 在bash脚本中如何检查一个命令是否存在 问: 如何验证程序是否存在,以一种要么返回错误并退出,要么继续执行脚本的方式? 这看起来应该很容易,但它一直困扰着我。......
/bin/bashFILE=$1if[ -f$FILE];thenecho"File$FILEexists."elseecho"File$FILEdoes not exist."fi 如何仅检查文件不存在? test命令(这里写作[)有一个 "not" 逻辑运算符,即感叹号!: if[ ! -f /tmp/foo.txt ];thenecho"File not found!"fi
-n abc : The string length is not 0 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 ec...
if [ -f filename ]then echo file exist else echo file not exist fi
if [ -e "/path/to/file" ]; then echo "File exists." else echo "File does not ...
This is the job of the test command, which can check if a file exists and its type. Since only the check is completed, the test command sets the exit code to 0 or 1 (either false or true, respectively) whether the test is successful or not. ...
然后构造一个 ls 命令来判断,不需要反单引号包围,套到 if 语句里: $ if ls exists.txt; then echo yes; else echo no; fi exists.txt yes $ if ls not_exists.txt; then echo yes; else echo no; fi ls: cannot access not_exists.txt: No such file or directory no ...
if [[ -f "$FILE" ]];then echo "$FILE exist" fi 如果要根据文件是否存在执行不同的操作,只需使用if / then结构: FILE=/etc/resolv.conf if [ -f "$FILE" ];then echo "$FILE exist" else echo "$FILE does not exist" fi 注:在处理名称中包含空格的文件时,请始终使用双引号以避免出现问题。
TestFile1 does not exist or is empty. 现在创建一个空文件用来测试: [student@studentvm1 testdir]$ File="TestFile1" ; touch $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ; fi ...
mysql -u root -p"$MYSQL_ROOT_PASS" -e "CREATE DATABASE IF NOT EXISTS $MYSQL_DB; GRANT ALL PRIVILEGES ON $MYSQL_DB.* TO $MYSQL_DB@localhost;"ERROR 1064 (42000) at line 1: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version fo ...