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Takeaways
# Arithmetic
local sum=$(($a + 5))
if (($age > $max_age)); then
# Conditionals
if [[ -f $file ]]; then
// elif/else/fi
# -d (dir)
# Pipes
trace=$(cat $file | grep Akamai)](https://image.slidesharecdn.com/bashfordevops-221110114543-dfb578d1/85/Bash-the-1-skill-for-Devops-Engineers-15-320.jpg)
![tag.sh
Takeaways
# Print line
before executing
[[ "$TRACE" ]] && set -x
# Trim all 'v' from left
new_version=${1##v}
# '%' from right
# Echo to stderr
echoerr() { echo "$@" 1>&2; }
# Command with if
if ! grep $version ./r.md; then
# AWK
awk "/^#.*$new_version/{flag=1;next}/^#/{flag=0}flag" $file](https://image.slidesharecdn.com/bashfordevops-221110114543-dfb578d1/85/Bash-the-1-skill-for-Devops-Engineers-19-320.jpg)
![tag.sh
Takeaways
# Git multiple -m
git commit -am "Release $new_version" -m "$description"
# Git return values
if ! git diff --quiet HEAD; then
# sed
sed -i.bak -E "s/[0-9]+.[0-9]+.[0-9]+/$new_version/g" $file](https://image.slidesharecdn.com/bashfordevops-221110114543-dfb578d1/85/Bash-the-1-skill-for-Devops-Engineers-21-320.jpg)
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