Superscripts

A bunch of scripts for all kind of purposes... :-)

Thing I like

These are just .sh or .bash scripts, but also such scripts have many little tricks you only learn over times.

To require an argument for a script:

file=${1:? "$0 requires \"file\" as first argument"}

Lowercase:

var_lc=$(echo $var | tr "[:upper:]" "[:lower:]")

Remove temporary file or directory, even if script fails:

tmpdir=$(mktemp -d -t prefixXXXXX)
trap 'rm -rf "$tmpdir"' EXIT

Create array from variable array_txt:

IFS=$'\n' read -d '' -r -a array <<< "$array_txt"

And of course its length:

array_length=${#array[@]}

Disable globbing:

shopt -s nullglob

Remove comma from last line in file:

sed -i -e '$s|,||' "$file"

Split a file based on context lines (for example a json array):

csplit -s -n6 -f "$file" '/metadata/-1' '{*}'

Json manipulations, use underscore-cli, say input is input.json and we want to get the field items and then snippet:

< input.json underscore select '.items .snippet' > result.json

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