set

هذا الجزء لم يُترجم بعد. أنت ترى النص الإنجليزي.

ماذا يفعل

set -OPTION turns an option on, set +OPTION turns it off. In scripts the most used line is set -euo pipefail (stop on errors, error on unset variables, fail on broken pipes). set -- a b c sets $1 $2 $3. Without arguments, set prints all shell variables and functions.

طريقة الكتابة

set [-abefhkmnptuvxBCEHPT] [-o OPTION] [--] [ARGUMENT]...

الخيارات 23

الأكثر استخدامًا

-e, -o errexit: Exit when a command fails.
-u, -o nounset: Error when an unset variable is used.
-x, -o xtrace: Print commands before running them (trace).
-o pipefail: A pipe fails if any command in it fails.
-v, -o verbose: Print lines as they are read.
-n, -o noexec: Read commands but do not run them.
-f, -o noglob: No wildcard expansion.
-C, -o noclobber: > does not overwrite files (use >| to force).
-a, -o allexport: Export all new variables.
-b, -o notify: Report finished jobs at once.
-h, -o hashall: Remember command locations.
-k, -o keyword: All assignments go to the environment.
-m, -o monitor: Job control.
-p, -o privileged: Privileged mode.
-t, -o onecmd: Exit after one command.
-B, -o braceexpand: Brace expansion (on by default).
-E, -o errtrace: ERR traps in functions.
-H, -o histexpand: ! history expansion.
-P, -o physical: No symlinks for cd and pwd.
-T, -o functrace: DEBUG/RETURN traps in functions.
-o vi, -o emacs: Editing mode of the command line.
-o: List all options and their state.
--: Set the positional parameters (or clear them).

أمثلة 10

$ مستخدم عادي# بصلاحية root (أو مع sudo)

1Strict mode for scripts

$head -2 /usr/local/bin/backup.sh
#!/bin/bash
set -euo pipefail

Many hidden errors become visible.

2Trace part of a script
```
$set -x; cp a b; set +x
+ cp a b
```
Only these lines are traced.

3Stop on errors

$bash -c 'set -e; false; echo "not reached"'

The script ends at false.

4Unset variable error
```
$bash -c 'set -u; echo "$TYPO"'
bash: line 1: TYPO: unbound variable
```
Catches typos like rm -rf "$DIR/" with an empty DIR.
5Pipe failures
```
$bash -c 'set -o pipefail; false | true; echo $?'
1
```
Without pipefail the result would be 0.

6Do not overwrite files

$set -C; echo x > existing.txt
bash: existing.txt: cannot overwrite existing file

Protects against a wrong >.

7vi mode on the command line
```
$set -o vi
```
Esc, then vi keys to edit.
8Show all options
```
$set -o | head
```
on/off for each.
9Set positional parameters
```
$set -- one two three; echo "$2 / $#"
two / 3
```
Useful in tests and functions.
10List variables and functions
```
$set | grep ^HIST
```
All HIST variables.

رموز الخروج

`0`	Done.
`1`	Wrong option.

`set`

ماذا يفعل

طريقة الكتابة

الخيارات 23

أمثلة 10

1Strict mode for scripts

2Trace part of a script

3Stop on errors

4Unset variable error

5Pipe failures

6Do not overwrite files

7vi mode on the command line

8Show all options

9Set positional parameters

10List variables and functions

رموز الخروج

الدليل الكامل

ماذا يفعل

طريقة الكتابة

الخيارات 23

أمثلة 10

1Strict mode for scripts

2Trace part of a script

3Stop on errors

4Unset variable error

5Pipe failures

6Do not overwrite files

7vi mode on the command line

8Show all options

9Set positional parameters

10List variables and functions

رموز الخروج

أوامر مرتبطة

مُستخدم في هذه الدروس

الدليل الكامل

`set`