while read -r line; do COMMAND; done < input.file 通过-r 选项传递给 read 命令以防止阻止解释其中的反斜杠转义符。 在read 命令之前添加 IFS= 选项,来防止首尾的空白字符被去掉。 while IFS= read -r line; do COMMAND_on $line; done < input.file 这是更适合人类阅读的语法: #!/bin/bash input...
=’.Whenitisused, the stringtotherightofthe operatorisconsidered a POSIX extended regular expressionandmatched accordingly (usingthe POSIX regcompandregexec interfaces usually describedinregex(3)). Thereturnvalueis0if the stringmatchesthepattern,and1otherwise. If the regular expressionissyntactically incorre...
Checking concatenation success: After concatenation, the script checks the exit status ($?) to determine if the operation was successful ($? -eq 0). If successful, it prints a message indicating successful concatenation; otherwise, it prints a failure message. 9. Remove Empty Lines: Write a ...
- Test if the specified variable has an empty value: [[ -z $variable ]] - Test if the specified [f]ile exists: [[ -f path/to/file ]] - Test if the specified [d]irectory exists: [[ -d path/to/directory ]] - Test if the specified file or directory [e]xists: [[ -e path...
Bash attempts to determine when it is being run by the remote shell daemon, usually rshd. If bash determines it is being run by rshd, it reads and executes commands from ~/.bashrc, if that file exists and is readable. It will not do this if invoked as sh. The --norc option may...
In this mode, interactive shells expand the ENV variable and commands are read and executed from the file whose name is the expanded value. No other startup files are read. Bash attempts to determine when it is being run with its standard input connected to a a network connection, as if ...
local size=$(du -b "$log_file" | cut -f1) # Check if the size exceeds the maximum size if [ "$size" -gt "$max_size" ]; then echo "Log file $log_file exceeds maximum size, rotating..." # Determine the next available log file name ...
For Solution 1, you can determine the file type using the file command. If the file is a tar file, the output will indicate that. You can then check the output using grep to see if it contains a tar archive. If the file does not exist, the file output will contain an exit code ...
If file existsif[[ -f "$_db" ]]then# read itwhileIFS='|'read -r pdfid pdfurl pdftitledolocalpdf="$o/$pdfid.pdf"echo"Creating$pdffile ..."#Genrate pdf file$_writer--quiet--footer-spacing 2 \--footer-left "nixCraft is GIT UL++++W+++C++++M+e+++d-" \--footer-right"...
Bash attempts to determine when it is being run with its standard input connected to a network connection, as when executed by the remote shell daemon, usually rshd, or the secure shell daemon sshd. If bash determines it is being run in this fashion, it reads ...