Use short form of grep's quiet flag

[sachatelgenhof]

In one of our projects we are using Alpine Linux and the version of grep included does not recognize the long form of the quiet flag ('--quiet'). Perhaps it is better to use the shorthand form as that seems to be more supported (unconfirmed with other versions or OS though).

OS version: Alpine Linux v3.16
Linux: Linux 081aed2eda30 6.2.8-arch1-1 #1 SMP PREEMPT_DYNAMIC Wed, 22 Mar 2023 22:52:35 +0000 x86_64 Linux

Output from our smoke test script running under Alpine Linux

grep: unrecognized option: quiet
BusyBox v1.35.0 (2022-08-01 15:14:44 UTC) multi-call binary.
Usage: grep [-HhnlLoqvsrRiwFE] [-m N] [-A|B|C N] { PATTERN | -e PATTERN... | -f FILE... } [FILE]...
Search for PATTERN in FILEs (or stdin)
	-H	Add 'filename:' prefix
	-h	Do not add 'filename:' prefix
	-n	Add 'line_no:' prefix
	-l	Show only names of files that match
	-L	Show only names of files that don't match
	-c	Show only count of matching lines
	-o	Show only the matching part of line
	-q	Quiet. Return 0 if PATTERN is found, 1 otherwise
	-v	Select non-matching lines
	-s	Suppress open and read errors
	-r	Recurse
	-R	Recurse and dereference symlinks
	-i	Ignore case
	-w	Match whole words only
	-x	Match whole lines only
	-F	PATTERN is a literal (not regexp)
	-E	PATTERN is an extended regexp
	-m N	Match up to N times per file
	-A N	Print N lines of trailing context
	-B N	Print N lines of leading context
	-C N	Same as '-A N -B N'
	-e PTRN	Pattern to match
	-f FILE	Read pattern from file