From 572dd8f96c738141ea508d7995557f04c9a8c9d7 Mon Sep 17 00:00:00 2001
From: Jim Huang <jserv@ccns.ncku.edu.tw>
Date: Sun, 9 Mar 2025 03:30:29 +0800
Subject: [PATCH] Fix BSD compatibility

On macOS, Perl-compatible regex option (-P) in GNU grep is not available
by default. It can be replaced with sed. While using 'tr', it is
necessary to set the locale to "C" ensures that tr interprets the byte
stream in a consistent, ASCII-only manner. This prevents errors like
"Illegal byte sequence" on BSD systems such as macOS.

Change-Id: I1c134092a5fb2afc8018a638e172fb0b380e0fdd
---
 scripts/check-repo.sh | 5 ++---
 scripts/common.sh     | 4 ++--
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/scripts/check-repo.sh b/scripts/check-repo.sh
index b0f9846bd..69b428c2b 100755
--- a/scripts/check-repo.sh
+++ b/scripts/check-repo.sh
@@ -65,7 +65,7 @@ REPO_NAME="lab0-c"
 repo_html=$(curl -s "https://github.com/${REPO_OWNER}/${REPO_NAME}")
 
 # Extract the default branch name from data-default-branch="..."
-DEFAULT_BRANCH=$(echo "$repo_html" | grep -oP "/${REPO_OWNER}/${REPO_NAME}/blob/\K[^/]+(?=/LICENSE)" | head -n 1)
+DEFAULT_BRANCH=$(echo "$repo_html" | sed -nE "s#.*${REPO_OWNER}/${REPO_NAME}/blob/([^/]+)/LICENSE.*#\1#p" | head -n 1)
 
 if [ "$DEFAULT_BRANCH" != "master" ]; then
   echo "$DEFAULT_BRANCH"
@@ -80,8 +80,7 @@ curl -sSL -o "$temp_file" "$COMMITS_URL"
 
 # general grep pattern that finds commit links
 upstream_hash=$(
-  grep -Po 'href="[^"]*/commit/\K[0-9a-f]{40}' "$temp_file" \
-  | head -n 1
+  sed -nE 's/.*href="[^"]*\/commit\/([0-9a-f]{40}).*/\1/p' "$temp_file" | head -n 1
 )
 
 rm -f "$temp_file"
diff --git a/scripts/common.sh b/scripts/common.sh
index bb6353ebf..a41097b95 100644
--- a/scripts/common.sh
+++ b/scripts/common.sh
@@ -89,14 +89,14 @@ make_random_string() {
 
   if [ -z "$sub_str" ]; then
     # Produce an exact random string of length total_len
-    cat /dev/urandom | tr -dc 'a-z0-9' | head -c "$total_len"
+    cat /dev/urandom | LC_ALL=C tr -dc 'a-z0-9' | head -c "$total_len"
   else
     # Insert the substring at a random position
     local sub_len=${#sub_str}
     local rand_len=$(( total_len - sub_len ))
 
     local raw_rand
-    raw_rand=$(cat /dev/urandom | tr -dc 'a-z0-9' | head -c "$rand_len")
+    raw_rand=$(cat /dev/urandom | LC_ALL=C tr -dc 'a-z0-9' | head -c "$rand_len")
 
     local pos=$(( RANDOM % (rand_len + 1) ))
     echo "${raw_rand:0:pos}${sub_str}${raw_rand:pos}"