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Diffstat (limited to '3 Resources/Bash')
-rw-r--r-- | 3 Resources/Bash/Expansion.md | 9 | ||||
-rw-r--r-- | 3 Resources/Bash/Generate random integers.md | 19 | ||||
-rw-r--r-- | 3 Resources/Bash/Heredoc.md | 16 |
3 files changed, 44 insertions, 0 deletions
diff --git a/3 Resources/Bash/Expansion.md b/3 Resources/Bash/Expansion.md new file mode 100644 index 0000000..1cd3209 --- /dev/null +++ b/3 Resources/Bash/Expansion.md @@ -0,0 +1,9 @@ +--- +tags: + - bash +--- +Find about in the manual `man bash` (search EXPANSION). This document will hold some often used expansions. + +**Variable expansion** +substr +`${VAR:offset:len}`
\ No newline at end of file diff --git a/3 Resources/Bash/Generate random integers.md b/3 Resources/Bash/Generate random integers.md new file mode 100644 index 0000000..8835716 --- /dev/null +++ b/3 Resources/Bash/Generate random integers.md @@ -0,0 +1,19 @@ +--- +tags: + - bash +--- +The environment variable `RANDOM` contains an int between 0-32768. + +``` +min=10 +max=20 +echo $(($RANDOM%($max-$min+1)+$min)) +20 +echo $(($RANDOM%($max-$min+1)+$min)) +14 +``` + +Using parameter [[Expansion]] we can just grab the first number: +``` +${RANDOM:0} +```
\ No newline at end of file diff --git a/3 Resources/Bash/Heredoc.md b/3 Resources/Bash/Heredoc.md new file mode 100644 index 0000000..703e3e5 --- /dev/null +++ b/3 Resources/Bash/Heredoc.md @@ -0,0 +1,16 @@ +``` +read -r -d '' VAR <<EOF +blaat +EOF +``` + +``` +var=$( +cat <<EOF +blaat +EOF +) +``` + +Quote EOF/NAME to prevent expansion +Put - after << to remove indentation from result
\ No newline at end of file |