implement inline comments

Makefile

@@ -28,7 +28,7 @@ MANPREFIX ?= ${PREFIX}/share/man
 all: dotenv
 
 dotenv: dotenv.c
-	${CC} -Os -o dotenv dotenv.c
+	${CC} -Os -Wall -Werror -o dotenv dotenv.c
 
 clean:
 	rm -f dotenv

README.md

@@ -56,11 +56,11 @@ Same as above but with a custom dotenv file path:
 
 The file format is a list of key-value pairs, one per line.
 The key and value are separated by an equal sign.
-Whitespaces around the key and value are ignored.
+Whitespaces around keys and values are ignored.
 A line is terminated by a newline character or a carriage return.
-Empty lines and lines starting with a hash sign (#) are ignored.
+Comments can be added using a hash sign (#) either at the start of a line
+or inline. For values that contain a hash sign, the value must be quoted.
 Values can be optionally quoted with single or double quotes.
-Characters after the ending quote for a value are ignored.
 If quoted, the following escape sequences are supported:
 
 \n
@@ -96,6 +96,7 @@ env(1)
 Yifan Gu <[[email protected]](mailto:[email protected])>
 
 Unknown OS - April 28, 2024
+
 # INSTALL
 
 ```bash

dotenv.1

@@ -73,11 +73,11 @@ $ DOTENV_PATH=.env2 dotenv env
 .Sh FILE FORMAT
 The file format is a list of key-value pairs, one per line.
 The key and value are separated by an equal sign.
-Whitespaces around the key and value are ignored.
+Whitespaces around keys and values are ignored.
 A line is terminated by a newline character or a carriage return.
-Empty lines and lines starting with a hash sign (#) are ignored.
+Comments can be added using a hash sign (#) either at the start of a line
+or inline. For values that contain a hash sign, the value must be quoted.
 Values can be optionally quoted with single or double quotes.
-Characters after the ending quote for a value are ignored.
 If quoted, the following escape sequences are supported:
 .Bl -tag -width \e'
 .It \en

dotenv.c

@@ -82,16 +82,22 @@ static inline int read_file(const char *filename, char **buffer, unsigned long *
 	return rc;
 }
 
-static inline void skip_charset(char **cur, const char *end, const char *charset) {
+static inline int skip_charset(char **cur, const char *end, const char *charset) {
+	int count = 0;
 	while (*cur < end && strchr(charset, **cur) != NULL) {
 		(*cur)++;
+		count++;
 	}
+	return count;
 }
 
-static inline void skip_until_charset(char **cur, const char *end, const char *charset) {
+static inline int skip_until_charset(char **cur, const char *end, const char *charset) {
+	int count = 0;
 	while (*cur < end && strchr(charset, **cur) == NULL) {
 		(*cur)++;
+		count++;
 	}
+	return count;
 }
 
 int main(int argc, const char *argv[]) {
@@ -144,7 +150,7 @@ int main(int argc, const char *argv[]) {
 		}
 
 		key = cur;
-		skip_until_charset(&cur, end, " \t=");
+		skip_until_charset(&cur, end, " \t=\r\n");
 		if (cur >= end) {
 			fprintf(stderr, "Unexpected end of file after key \"%s\"\n", key);
 			rc = 1;
@@ -154,6 +160,7 @@ int main(int argc, const char *argv[]) {
 		skip_charset(&cur, end, " \t");
 
 		if (*cur != '=' && *cur != '\0') {
+			*cur = '\0';
 			fprintf(stderr, "Missing equal after key \"%s\"\n", key);
 			rc = 1;
 			goto end;
@@ -183,9 +190,9 @@ int main(int argc, const char *argv[]) {
 
 			while (cur < end) {
 				if (*cur == '\\') {
-					cur++; // skip escape character
+					cur++;
 					if (cur >= end) {
-						fprintf(stderr, "Unexpected end of file after escape character at key \"%s\"\n", key);
+						fprintf(stderr, "Unexpected end of file after escape character\n");
 						rc = 1;
 						goto end;
 					}
@@ -233,15 +240,29 @@ int main(int argc, const char *argv[]) {
 				goto end;
 			}
 
-			key_end = inner_cur;
+			value_end = inner_cur;
 			cur++;
+			skip_charset(&cur, end, " \t");
+			if (skip_until_charset(&cur, end, "#\r\n") > 0) {
+				fprintf(stderr, "Unexpected characters after closing quote\n");
+				rc = 1;
+				goto end;
+			}
+			skip_until_charset(&cur, end, "\r\n");
 		} else {
+			value_end = NULL;
 			value = cur;
 			// unquoted value
+			while (skip_until_charset(&cur, end, "# \t\r\n") && strchr("#\r\n", *cur) == NULL) {
+				value_end = cur;
+				cur++;
+			}
+			if (value_end == NULL) {
+				value_end = cur;
+			}
 			skip_until_charset(&cur, end, "\r\n");
-			key_end = cur;
 		}
-		*key_end = '\0';
+		*value_end = '\0';
 
 		rc = setenv(key, value, 1);
 		if (rc != 0) {