From 80ccf68f55dbb70d7e5ed52ee95b3c9d1b6ce264 Mon Sep 17 00:00:00 2001
From: Jasper Ras <jras@hostnet.nl>
Date: Thu, 20 Mar 2025 11:07:49 +0100
Subject: vault backup: 2025-03-20 11:07:48

---
 3 Resources/Bash/Expansion.md                |  9 +++++++++
 3 Resources/Bash/Generate random integers.md | 19 +++++++++++++++++++
 3 Resources/Bash/Heredoc.md                  | 16 ++++++++++++++++
 3 files changed, 44 insertions(+)
 create mode 100644 3 Resources/Bash/Expansion.md
 create mode 100644 3 Resources/Bash/Generate random integers.md
 create mode 100644 3 Resources/Bash/Heredoc.md

(limited to '3 Resources/Bash')

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
-- 
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