How to Check if File exists and is Empty in Bash When working with shell scripts, it’s important to be able to check if a file exists and if it’s empty or not. This is especially useful when automating tasks that rely on specific files being present and non-empty, here is an exam...
All the code snippets are written in the MyScript.sh file, while the dummy.txt file contains some sample data we used in our scripts. Using -q Option with grep Use the -q option with grep to check if the grep command result is empty. Use -q Option with grep in MyScript.sh 1 2...
我有一个python脚本,它需要检查日志文件是否为空或其中是否有日志。我使用os.system来运行bash命令,找到这个命令是为了查看文件是否为空:thenelseecho "File empty"我试着在os.system命令的一 浏览0提问于2020-11-11得票数 0 2回答 无法运行bash脚本示例从“linux命令行,一个完整的介绍,第二” 、、、 /bin/...
we are using the Bash instruction to run this Bash file, i.e., empty.sh. On execution, it returns “Empty” because the string “str” is initialized empty in the code, and the “then” part of the “if-else” statement has been executed so far. ...
if [[ - f <file 1> ]] && [[-f <file> ]] then echo "file exists!" fi. Easy! Make sure to remember the “-f” command and file name you’re looking for. Check if a File Does Not Exist The next one you’ll need to learn is to check if a file exists no more. The comm...
# -f 参数判断 $file 是否存在 if [ ! -f "$file" ]; then touch "$file" fi # -n 判断一个变量是否有值 if [ ! -n "$var" ]; then echo "$var is empty" exit 0 fi # 判断两个变量是否相等 if [ "$var1" = "$var2" ]; then ...
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 Any File with Extension Exists inbash In all previousbashscript examples, the name of the file to check is pre-determined and known. What if you want to check if any file with a pattern (e.g., with a particular extension) exists? In that case, the name of file(s) to che...
echo "File not found" fi Run Below command to check $ sh filecheck.sh /tmp/users.txt Check if file exists if [ -f /tmp/users.txt ]; then echo "File is exist" fi Expressions used with if The table below contains an overview of the so-called “primaries” that make up theTEST-COM...
Check to see if a variable is empty or not Create a new bash file, named, and enter the script below. The script above stores the first command-line argument in a variable and then tests the argument in the next statement. This script will print the first argument because it is not em...