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moves coding challenge to end of chapter

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waldek 2022-05-20 15:56:52 +02:00
parent 2560bf39ad
commit 7d391db0d9
1 changed files with 32 additions and 31 deletions
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advanced/learning_bash_scripting.md
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@ -812,6 +812,38 @@ if [ "$num" -lt "300" ]; then
fi
```
## A *modern* version of `test`
I'll be the first to admit that the syntax of `bash` can be confusing and is rarely reader friendly.
A nice, but brief, explication of the nuances of single and double brackets can be found in [this](https://unix.stackexchange.com/questions/306111/what-is-the-difference-between-the-bash-operators-vs-vs-vs) stack overflow post.
The double bracket command are called [compound commands](https://www.gnu.org/software/bash/manual/html_node/Compound-Commands.html).
### `[[ ]]`
```
waldek@debian:~$ [[ 3 = [[:digit:]] ]] ; echo $?
0
waldek@debian:~$ [ 3 = [[:digit:]] ] ; echo $?
1
```
TODO
### `(( ))`
TODO
### `&&` and `||`
```
waldek@debian:~$ test true == true && echo "yes sir!" || echo "nope..."
yes sir!
waldek@debian:~$ test true == false && echo "yes sir!" || echo "nope..."
nope...
waldek@debian:~$
```
[Ryan's tutorials](https://ryanstutorials.net/bash-scripting-tutorial/bash-if-statements.php)
# Coding challenge - File information
Write a script that takes one argument which should be a valid file path.
@ -868,37 +900,6 @@ fi
</details>
## A *modern* version of `test`
I'll be the first to admit that the syntax of `bash` can be confusing and is rarely reader friendly.
A nice, but brief, explication of the nuances of single and double brackets can be found in [this](https://unix.stackexchange.com/questions/306111/what-is-the-difference-between-the-bash-operators-vs-vs-vs) stack overflow post.
The double bracket command are called [compound commands](https://www.gnu.org/software/bash/manual/html_node/Compound-Commands.html).
### `[[ ]]`
```
waldek@debian:~$ [[ 3 = [[:digit:]] ]] ; echo $?
0
waldek@debian:~$ [ 3 = [[:digit:]] ] ; echo $?
1
```
TODO
### `(( ))`
TODO
### `&&` and `||`
```
waldek@debian:~$ test true == true && echo "yes sir!" || echo "nope..."
yes sir!
waldek@debian:~$ test true == false && echo "yes sir!" || echo "nope..."
nope...
waldek@debian:~$
```
[Ryan's tutorials](https://ryanstutorials.net/bash-scripting-tutorial/bash-if-statements.php)
# Loops - A variety of ways to perform repetitive tasks.