Wild Cards in Linux - Every Beginner should know
Here are some mostly used wild cards in Linux
Hello, techies!
Welcome to my article on Linux wildcards, wildcards are symbols or set of symbols used to substitute in place of a character or characters for the pattern match in a string.
| Wildcard | Description |
| ? | denote single character |
| ???? | to specify number of character of that filename size |
| * | every thing or all |
| [] | represent range |
| ls m[a-d]n | file start with m and end with n having charcter including a to d |
| {.doc,.pdf} | match all doc file and pdf file |
| [!9] | ignore 9 or don't match 9 |
| \ | string literal skip |
| touch \ | to create a file name \ |
| $1, $2, $3, ... | are the positional parameters |
| "$@" | is an array-like construct of all positional parameters, {$1, $2, $3 ...} |
| "$*" | is the IFS expansion of all positional parameters, $1 $2 $3 .... |
| $# | is the number of positional parameters |
| $- | current options set for the shell |
| $$ | PID of the current shell (not subshell) |
| $IFS | is the (input) field separator |
| $? | is the most recent foreground pipeline exit status |
| $! | is the PID of the most recent background command |
| $0 | is the name of the shell or shell script |
| $_ | most recent parameter (or the abs path of the command to start the current shell immediately after startup) |
Thank you for reading!
Sources: Ref