f FILE—— 如果 ref="https://linuxize.com/post/bash-check-if-file-exists/">FILE 存在,并且是常规文件(不是目录或设备什么的) ,则为真。 结论 if、if..else 和if..elif..else 语句让我们能够基于不同的判断条件来控制 Bash 脚本中逻辑语句的执行。 如果你有任何疑问或反馈,请随时发表评论。
-u filename - Check if file set-user-id bit is set -w filename - Check if file is writable -x filename - Check if file is executable How to use: #!/bin/bash file=./file if [ -e "$file" ]; then echo "File exists" else echo "File does not exist" fi A test expression ...
/bin/bash file="/path/to/file.txt" if [ -f "$file" ] && [ -r "$file" ] && [ -w "$file" ]; then echo "$file exists and is readable and writable." else echo "$file either does not exist or is not readable or writable." fi ``` 在上面的示例中,我们组合了三个条件:文件...
if [ -f "$file" ]; then echo "$file exists." else echo "$file does not exist." fi ``` 在上述示例中,我们首先定义了一个变量`file`,并赋值为指定文件的路径。然后使用`-f`参数进行判断,如果文件存在,则输出`$file exists.`,否则输出`$file does not exist.`。 除了判断文件是否存在外,我们还...
if [ -e "$file_path" ]; then echo "The file exists." else echo "The file does not exist." fi If-elif-else Statement 在bash 脚本中,如果希望使用 if 语句应用多个条件,则使用 if elif else。在这种类型的条件语句中,如果满足第一个条件,则执行下面的代码,否则检查下一个 if 条件,如果不匹配,...
I have a bash program that will write to an output file. This file may or may not exist, but the script must check permissions and fail early. I can't find an elegant way to make this happen. Here's what I have tried. set +e touch $file set -e if [ $?...
一般bash 教程给出的语法示例基本就是: if condition; then echo yes else echo no fi 看起来很简单,除了condition外(也就是条件部分),其余关键字都没什么难懂了,顶多注意一下写在同一行要加分号。 但条件部分代码说得不明不白,只是列出一堆实际例子,例如判断文件存在可以用[ -f file ],判断目录用[ -d ...
After saving the file, open the terminal and execute the source FileName.sh command to run the bash script file. Note that the following conditional commands can be used to check and create a folder if it does not exist in bash. Using if Statement The if conditional statement tests whether...
[ FILE1 -nt FILE2 ] 如果 FILE1 has been changed more recently than FILE2, or 如果 FILE1 exists and FILE2 does not则为真。 [ FILE1 -ot FILE2 ] 如果 FILE1 比 FILE2 要老, 或者 FILE2 存在且 FILE1 不存在则为真。 [ FILE1 -ef FILE2 ] 如果 FILE1 和 FILE2 指向相同的设备和节...
When writing Shell scripts, you may find yourself in a situation where you need to perform an action based on whether a file exists or not. In Bash, you can use the test command to check whether a file exists and determine the type of the file....