Checking c compiler (from musl configure)

checkc.sh

#!/bin/sh

echo () { printf "%s\n" "$*" ; }
fail () { echo "$*" ; exit 1 ; }
fnmatch () { eval "case \"\$2\" in $1) return 0 ;; *) return 1 ;; esac" ; }
cmdexists () { type "$1" >/dev/null 2>&1 ; }
trycc () { test -z "$CC" && cmdexists "$1" && CC=$1 ; }

printf "checking for C compiler... "
trycc ${CROSS_COMPILE}gcc
trycc ${CROSS_COMPILE}c99
trycc ${CROSS_COMPILE}cc
printf "%s\n" "$CC"
test -n "$CC" || { echo "$0: cannot find a C compiler" ; exit 1 ; }

printf "checking for C compiler family... "
cc_ver="$(LC_ALL=C $CC -v 2>&1)"
cc_family=unknown
if fnmatch '*gcc\ version*' "$cc_ver" ; then
cc_family=gcc
elif fnmatch '*clang\ version*' "$cc_ver" ; then
cc_family=clang
fi
echo "$cc_family"