| Action | Command | Details |
|---|---|---|
| Shebang | #!/bin/bash |
Defines the script interpreter. |
| Variable assignment | VAR=value |
Assign a value to a variable. |
| Print to console | echo 'Hello World' |
Display text output. |
| Read input | read var |
Read user input into variable. |
| If statement | if [ condition ]; then ... fi |
Conditional execution. |
| For loop | for i in {1..5}; do ... done |
Loop through a sequence. |
| While loop | while [ condition ]; do ... done |
Loop while condition is true. |
| Function definition | function_name() { commands; } |
Define reusable code block. |
| Exit script | exit 0 |
Exit script with status code. |
| Command substitution | VAR=$(command) |
Capture command output. |
| Test file existence | [ -f filename ] |
Check if file exists. |
| Check string equality | [ "$var" == "value" ] |
String comparison. |
| Arrays | arr=(val1 val2 val3) |
Define an array. |
| Access array element | ${arr[0]} |
Get element at index. |
| Redirect output | command > file.txt |
Overwrite file with command output. |
| Append output | command >> file.txt |
Append command output to file. |
| Pipe commands | command1 | command2 |
Send output of one command to another. |
| Background process | command & |
Run command in the background. |
| Get script arguments | $1, $2, ... |
Access positional parameters. |