if [ -e "/path/to/file" ]; then echo "File exists." else echo "File does not exis...
/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
[root@smsgw root]#chmod +x if_4.sh [root@smsgw root]#./if_4.sh usage: ./if_4.sh <file> [root@smsgw root]#./if_4.sh hello [root@smsgw root]# 示例五 判断文件中是否包含某个字符串 if grep -q root /etc/passwd; then echo account root exists else echo account root not exis...
echo"3. Multiplication"echo-n"Please choose a word [1,2 or 3]? "read operif[$oper-eq1]then echo"Addition Result "$(($inp1+$inp2))elseif[$oper-eq2]then echo"Subtraction Result "$(($inp1-$inp2))elseif[$oper-eq3]then echo"Multiplication Result "$(($inp1*$inp2))elseecho"Inva...
解释:if后面的条件测试返回的状态码为0,则执行程序体中的语句;若返回的状态码为非0,则执行else下面程序体中的语句。 例4:如果指定用户存在,先说明其存在并显示ID号和shell;否则,就添加用户,并显示其ID #!/bin/bash#User=user2ifid$User&>/dev/null;thenecho"$Userexist"grep"$User"/etc/passwd|cut-d"...
/bin/bashFILE=$1 if [ -f $FILE ]; then echo "File $FILE exists." else echo "File $FILE does not exist." fi我如何只检查文件是否不存在?解决方案1:一个优秀的自由职业者,应该有对需求敏感和精准需求捕获的能力,而huntsbot.com centos提示bash命令找不到...
/bin/bashif[$#-ne 1 ];thenecho"Error: Invalid number of arguments"exit1fifile=$1if[ -f$file];thenecho"$fileis a regular file."elif[ -L$file];thenecho"$fileis a soft link."elif[ -d$file];thenecho"$fileis a directory."elseecho"$filedoes not exist"fi...
Check if the directory still exists The -d operator allows you to test if a file is a directory. For example, to check if the /etc/filetocheck directory exists, you can use: NOTE: You can also use double brackets [[ instead of [ single brackets. Check if the file doesn’t exist ...
if [ "$name" == "Alice" ] then echo "Hello, Alice!" else echo "You are not Alice." fi Example 3: File Check #!/bin/bash file_path="/path/to/file.txt" if [ -f "$file_path" ] then echo "File exists." else echo "File does not exist." ...
在bash中,只有变量的if语句会计算到什么? 、、 我正在学习bash --登录,并看到/etc/profile中的命令是首先执行的。$i donefi 当然,我对bash中的控制流有一个有限的理解,但根据我的理解,我在if语句中看到的大多数情况都是某种条件语句,是否是[-a FILENAME]来检查文件是否存在或字符串之间的</ 浏览0提问于201...