rcx

commit 0d8e1bf40232d129474377734a748561e49fd96f
parent 10821efb8b7d9688408de07f4dbd0078ed6ec2fa
Author: Robert Russell <robertrussell.72001@gmail.com>
Date:   Wed,  7 Sep 2022 14:49:50 -0700

Add cat and ecat functions

The interface of these is tentative. We may also add vcat and
evcat functions if the need arises.

Diffstat:
M
inc/rcx/str.h
 | 
3
+++
M
src/str.c
 | 
62
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-

2 files changed, 64 insertions(+), 1 deletion(-)
diff --git a/inc/rcx/str.h b/inc/rcx/str.h
@@ -8,6 +8,9 @@
 char *r_str_dup(char *s);
 char *r_str_edup(char *s);
 
+char *r_str_cat(char *buf, usize len, ...);
+char *r_str_ecat(char *buf, usize len, ...);
+
 bool r_str_starts_with(char *s, char *sub);
 bool r_str_ends_with(char *s, char *sub);
 
diff --git a/src/str.c b/src/str.c
@@ -1,5 +1,6 @@
 #define _ISOC99_SOURCE /* vsnprintf */
 #include <assert.h>
+#include <errno.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -8,7 +9,46 @@
 #include "rcx/rcx.h"
 #include "rcx/str.h"
 
-/* TODO: str to int converters */
+/* TODO: e-versions of every function that can fail */
+
+static char *
+r_str_vcat(char *buf, usize len, va_list args) {
+	assert(buf || len == 0);
+
+	char *s;
+	usize need = 1; /* Null terminator */
+
+	va_list args2;
+	va_copy(args2, args);
+	while ((s = va_arg(args2, char*))) {
+		usize slen = strlen(s);
+		if (slen > USIZE_MAX - need) {
+			va_end(args2);
+			errno = EOVERFLOW;
+			return 0;
+		}
+		need += slen;
+	}
+	va_end(args2);
+
+	if (buf && len < need) {
+		errno = ERANGE;
+		return 0;
+	} else if (!buf) {
+		buf = r_alloc(need);
+		if (!buf)
+			return 0;
+	}
+
+	char *b = buf;
+	while ((s = va_arg(args, char*))) {
+		while (*s)
+			*b++ = *s++;
+	}
+	*b = '\0';
+
+	return buf;
+}
 
 char *
 r_str_dup(char *s) {
@@ -25,6 +65,26 @@ r_str_edup(char *s) {
 	return dup;
 }
 
+char *
+r_str_cat(char *buf, usize len, ...) {
+	va_list args;
+	va_start(args, len);
+	char *ret = r_str_vcat(buf, len, args);
+	va_end(args);
+	return ret;
+}
+
+char *
+r_str_ecat(char *buf, usize len, ...) {
+	va_list args;
+	va_start(args, len);
+	char *ret = r_str_vcat(buf, len, args);
+	va_end(args);
+	if (!ret)
+		r_fatalf("r_str_ecat: %s", strerror(errno));
+	return ret;
+}
+
 bool
 r_str_starts_with(char *s, char *sub) {
 	return !strncmp(s, sub, strlen(sub));