How to check if a variable exists or is “null”? How to check if a file exists? How to check if a directory exists? How to check if a command succeeds or failed? How to do string comparison and check if a string equals to a value? How to check if a string is in an array?
directory="./BashScripting" # bash check if directory exists if [ -d $directory ]; then echo "Directory exists" else echo "Directory does not exists" fi 1. 2. 3. 4. 5. 6. 7. 8. 9. 9.2. Nested if/else #!/bin/bash # Declare variable choice and assign value 4 choice=4 # Pr...
# Function to check if a directory exists directory_exists() { local dirname="$1" if [ -d "$dirname" ]; then echo "Directory '$dirname' exists." else echo "Directory '$dirname' does not exist." fi } # Test the directory functions create_directory "workarea_dir" directory_exists "wo...
Check if the file exists Run one of the following commands to check if the file exists: 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...
-eq 等于,如:if [ "a"−eq"b" ] -ne 不等于,如:if [ "a"−ne"b" ] -gt 大于,如:if [ "a"−gt"b" ] -ge 大于等于,如:if [ "a"−ge"b" ] -lt 小于,如:if [ "a"−lt"b" ] -le 小于等于,如:if [ "a"−le"b" ] ...
可以通过...如果文件不存在,open 一.python判断文件和文件夹是否存在.创建文件夹 复制代码 代码如下: >>> import os >>> os.path.exists(‘d:/assist’) True.../floder’ if not tf.gfile.Exists(folder): #若文件夹不存在,则自动创建文件夹 tf.gfile.MakeDirs(folder) 若存在删除文件夹下所有文件...
#文件测试操作-d FILE_NAM # TrueifFILE_NAM is a directory-e FILE_NAM # TrueifFILE_NAM exists-f FILE_NAM # TrueifFILE_NAM existsandis a regular file-r FILE_NAM # TrueifFILE_NAM is readable-s FILE_NAM # TrueifFILE_NAM existsandisnotempty...
执行命令区域，否则 不进入循环，介绍while 命令 行3，执行命令区域，这些命令中，Bash，Unix shell的...
3. File and Directory Checks: -e: Exists -f: Regular file -d: Directory -r: Readable -w: Writable -x: Executable Example of using If Statement: Let’s illustrate the usage of if statements with a few examples: Example 1: Numeric Comparison ...
How can I check if a directory exists in a bash script? Use the if [ -d "dir" ]; then command to check if a directory named "dir" exists. How do I write scripts to run in the current directory? Use ./script.sh to run a script named "script.sh" in the current directory. The...