Relax SC2182 for bash, when printf -v is used

[jimbobmcgee]

Specifically for bash, printf has an extra option, -v which you can supply a variable name. This named variable is populated with the result of the printf call. This means you can write printf -vvar '%s x %s' "$1" "$2"; echo "$var".

Usually, the first arg to printf is a format string, so in POSIX shell, an equivalent might be var="$(printf '%s x %s' "$1" "$1")"; echo "$var".

SC2182 fires for bash if the first arg is -vvar, because -vvar does not contain any format string tokens. However, it is a valid argument to bash's printf.

For bugs

• Rule Id (if any, e.g. SC1000): SC2182
• My shellcheck version (shellcheck --version or "online"): 0.9 (according to https://github.com/vscode-shellcheck/vscode-shellcheck/releases/tag/v0.29.2)
• The rule's wiki page does not already cover this (e.g. https://shellcheck.net/wiki/SC2086)
• I tried on https://www.shellcheck.net/ and verified that this is still a problem on the latest commit

Here's a snippet or screenshot that shows the problem:

#!/bin/bash
printf -vvar '%s x %s' "$1" "$2"
echo "$var"

Here's what shellcheck currently says:

SC2182 (error): This printf format string has no variables. Other arguments are ignored.

Here's what I wanted or expected to see:

no error