From 030c80da6a9c04aa76ef76684fbff04e2390020f Mon Sep 17 00:00:00 2001
From: arslee07 <mail@arslee.me>
Date: Mon, 19 Aug 2024 00:20:55 +0900
Subject: [PATCH] POSIX compliance

According to the POSIX standard[0], the length() function only supports strings.
Although most common awk implementations support array length() as an
extension[1], it is better to make the program portable.

GNU Awk has a --posix flag that ensures that the script is POSIX compliant.
Running markdown.awk with this flag results in an error. This can be fixed by
getting the length of the array returned by split().

[0]: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/awk.html
[1]: https://www.gnu.org/software/gawk/manual/html_node/Common-Extensions.html
---
 markdown.awk | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/markdown.awk b/markdown.awk
index 293002f..73769ce 100755
--- a/markdown.awk
+++ b/markdown.awk
@@ -100,10 +100,10 @@ function parse_list(str,    buf, result, i, ind, line, lines, indent, is_bullet)
 	result = "";
 	buf = "";
 
-	split(str, lines, "\n");
+	num_lines = split(str, lines, "\n");
 
 	str = ""
-	for (i=1; i<=length(lines); i++) {
+	for (i=1; i<=num_lines; i++) {
 		line = lines[i];
 
 		if (match(line, /^[[:space:]]*[-+*][[:space:]]/) || 
@@ -113,7 +113,7 @@ function parse_list(str,    buf, result, i, ind, line, lines, indent, is_bullet)
 			str = join_lines(rstrip(str), lstrip(line), " ");
 	}
 
-	split(str, lines, "\n")
+	num_lines = split(str, lines, "\n")
 
 	indent = match(str, /[^ ]/);
 	is_bullet = match(str, /^[[:space:]]*[-+*][[:space:]]/)
@@ -123,7 +123,7 @@ function parse_list(str,    buf, result, i, ind, line, lines, indent, is_bullet)
 	else
 		result = "<ol>\n"
 
-	for (i=1; i<=length(lines); i++) {
+	for (i=1; i<=num_lines; i++) {
 		line = lines[i];
 
 		if (match(line, "[^ ]") > indent) {
@@ -367,10 +367,10 @@ function parse_line(str,    result, end, i, c) {
 }
 
 function parse_blockquote(str,    i, lines, line, buf, result) {
-	split(str, lines, "\n");
+	num_lines = split(str, lines, "\n");
 
 	str = ""
-	for (i=1; i<=length(lines); i++) {
+	for (i=1; i<=num_lines; i++) {
 		line = lines[i];
 
 		if (match(line, /^>/))
@@ -379,11 +379,11 @@ function parse_blockquote(str,    i, lines, line, buf, result) {
 			str = join_lines(rstrip(str), lstrip(line), " ");
 	}
 	
-	split(str, lines, "\n");
+	num_lines = split(str, lines, "\n");
 
 	result = "<blockquote>";
 	buf = "";
-	for (i=1; i<=length(lines); i++) {
+	for (i=1; i<=num_lines; i++) {
 		line = lines[i];
 		gsub(/^> ?/, "", line);
 
@@ -409,9 +409,9 @@ function parse_code(str,    i, lines, result) {
 	}
 	if (match(str, /^    /)) {
 		result = "";
-		split(str, lines, "\n");
+		num_lines = split(str, lines, "\n");
 
-		for (i=1; i<=length(lines); i++) {
+		for (i=1; i<=num_lines; i++) {
 			line = lines[i];
 			gsub(/^    /, "", line);
 			result = result "\n" line;
@@ -424,8 +424,8 @@ function parse_code(str,    i, lines, result) {
 }
 
 function is_metadata(str,    i, lines, line) {
-	split(str, lines, "\n");
-	for (i=1; i<=length(lines); i++) {
+	num_lines = split(str, lines, "\n");
+	for (i=1; i<=num_lines; i++) {
 		line = lines[i];
 
 		if (! match(line, /^[^ ]+: .+$/))
@@ -444,13 +444,13 @@ function col_count(str,    i, count) {
 
 }
 function is_table(str,    i, lines, line) {
-	split(str, lines, "\n");
+	num_lines = split(str, lines, "\n");
 	num_cols = col_count(lines[1]);
 	if (!match(lines[2], /^([[:space:]]*\|[[:space:]]*-{3,}[[:space:]])*\|[[:space:]]*/)) {
 		return 0;
 	}
 
-	for (i=2; i<=length(lines); i++) {
+	for (i=2; i<=num_lines; i++) {
 		line = lines[i];
 
 	    if (col_count(line) != num_cols)
@@ -461,7 +461,7 @@ function is_table(str,    i, lines, line) {
 }
 
 function parse_table(str, num_cols, lines, line, cols, i, j) {
-	split(str, lines, "\n");
+	num_lines = split(str, lines, "\n");
 	num_cols = col_count(lines[1]);
 
 	split(lines[1], cols, "|");
@@ -471,7 +471,7 @@ function parse_table(str, num_cols, lines, line, cols, i, j) {
     }
 	res = res "</tr>\n"
 
-	for (i=3; i<=length(lines); i++) {
+	for (i=3; i<=num_lines; i++) {
 		line = lines[i];
 	    split(line, cols, "|");
 	    res=res "<tr>\n";
@@ -515,11 +515,11 @@ function parse_block(str) {
 }
 
 function parse_body(str,    body, line, lines, result, i) {
-	split(str, lines, "\n");
+	num_lines = split(str, lines, "\n");
 	result = "";
 	body = "";
 
-	for (i=1; i<=length(lines); i++) {
+	for (i=1; i<=num_lines; i++) {
 		line = lines[i];
 		if (line_continues(body, line)) {
 			if (body != "")