Linux command
for 命令
文本
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常用示例
Iterate over list
for item in [a b c]; do echo $item; done
Loop over files
for file in *.txt; do cat "$file"; done
C-style loop
for ((i=0; i<10; i++)); do echo $i; done
Loop with range
for i in {1..10}; do echo $i; done
Process command output
for line in $(cat [file.txt]); do echo "$line"; done
说明
for is a shell keyword that iterates over a list of items, executing commands for each. It's one of the fundamental loop constructs in shell scripting. The loop variable takes each value from the word list in turn. Brace expansion, command substitution, and globbing can generate the list. C-style syntax provides numeric iteration. for loops are essential for batch processing files, generating sequences, and iterating over arrays.
参数
- in
- Introduces the list of items.
- do
- Begins the command block.
- done
- Ends the for loop.
FAQ
What is the for command used for?
for is a shell keyword that iterates over a list of items, executing commands for each. It's one of the fundamental loop constructs in shell scripting. The loop variable takes each value from the word list in turn. Brace expansion, command substitution, and globbing can generate the list. C-style syntax provides numeric iteration. for loops are essential for batch processing files, generating sequences, and iterating over arrays.
How do I run a basic for example?
Run `for item in [a b c]; do echo $item; done` in a terminal, then adjust file names, paths, flags, or remote targets for your system.
What does in do in for?
Introduces the list of items.