stringbuilder: Functions for joining strings.

[ccan] / ccan / stringbuilder / stringbuilder.c

diff --git a/ccan/stringbuilder/stringbuilder.c b/ccan/stringbuilder/stringbuilder.c
new file mode 100644 (file)
index 0000000..d34de81
--- /dev/null
+++ b/ccan/stringbuilder/stringbuilder.c
@@ -0,0 +1,77 @@
+/* CC0 (Public domain) - see LICENSE file for details */
+#include <ccan/stringbuilder/stringbuilder.h>
+#include <string.h>
+#include <errno.h>
+
+int stringbuilder_args(char* str, size_t str_sz, const char* delim, ...)
+{
+       int res;
+       va_list ap;
+       va_start(ap, delim);
+       res = stringbuilder_va(str, str_sz, delim, ap);
+       va_end(ap);
+       return res;
+}
+
+static int stringbuilder_cpy(
+               char** str, size_t* str_sz, const char* s, size_t s_len)
+{
+       if (!s)
+               return 0;
+
+       if (*str != s) {
+               if (!s_len)
+                       s_len = strlen(s);
+               if (s_len > *str_sz)
+                       return EMSGSIZE;
+               strcpy(*str, s);
+       }
+       *str += s_len;
+       *str_sz -= s_len;
+       return 0;
+}
+
+int stringbuilder_va(char* str, size_t str_sz, const char* delim, va_list ap)
+{
+       int res = 0;
+       size_t delim_len = 0;
+       const char* s = va_arg(ap, const char*);
+
+       if (delim)
+               delim_len = strlen(delim);
+
+       res = stringbuilder_cpy(&str, &str_sz, s, 0);
+       s = va_arg(ap, const char*);
+       while(s && !res) {
+               res = stringbuilder_cpy(&str, &str_sz,
+                               delim, delim_len);
+               if (!res) {
+                       res = stringbuilder_cpy(&str, &str_sz,
+                                               s, 0);
+                       s = va_arg(ap, const char*);
+               }
+       }
+       return res;
+}
+
+int stringbuilder_array(char* str, size_t str_sz, const char* delim,
+               size_t n_strings, const char** strings)
+{
+       int res = 0;
+       size_t delim_len = 0;
+
+       if (delim)
+               delim_len = strlen(delim);
+
+       res = stringbuilder_cpy(&str, &str_sz,
+                       *(strings++), 0);
+       while(--n_strings && !res) {
+               res = stringbuilder_cpy(&str, &str_sz,
+                               delim, delim_len);
+               if (!res)
+                       res = stringbuilder_cpy(&str, &str_sz,
+                                       *(strings++), 0);
+       }
+       return res;
+
+}