From eac902123e8c3cd454eec6b63e7828a5dd16d0e8 Mon Sep 17 00:00:00 2001
From: MDLeom <2809763-curben@users.noreply.gitlab.com>
Date: Sat, 20 May 2023 09:51:12 +0000
Subject: [PATCH] fix: check installed grep is GNU variant

---
 src/script.sh | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/script.sh b/src/script.sh
index 47246bcb..d18aadbb 100644
--- a/src/script.sh
+++ b/src/script.sh
@@ -7,17 +7,28 @@ set -efx -o pipefail
 alias curl="curl -L"
 alias rm="rm -rf"
 
-## Use GNU grep, busybox grep is too slow
+## Use GNU grep, busybox grep is not as performant
 . "/etc/os-release"
 DISTRO="$ID"
 
-if [ -z "$(grep --help | grep 'GNU')" ]; then
-  if [ "$DISTRO" = "alpine" ]; then
-    echo "Please install GNU grep 'apk add grep'"
-    exit 1
+check_grep() {
+  if [ -z "$(grep --help | grep 'GNU')" ]; then
+    if [ -x "/usr/bin/grep" ]; then
+      echo "grep found. try alias"
+      alias grep="/usr/bin/grep"
+      check_grep
+    else
+      if [ "$DISTRO" = "alpine" ]; then
+        echo "Please install GNU grep 'apk add grep'"
+      else
+        echo "GNU grep not found"
+      fi
+      exit 1
+    fi
   fi
-  alias grep="/usr/bin/grep"
-fi
+}
+
+check_grep
 
 
 ## Detect Musl C library