src/common.[ch]: Add the ssnprintf_alloc() function.

diff --git a/src/common.c b/src/common.c
index 79e4c02c631841334307222430e02d4bc381153d..d963efa556a6f60ce6f71c3472f90e791dc48c4e 100644 (file)
--- a/src/common.c
+++ b/src/common.c
@@ -86,6 +86,47 @@ int ssnprintf (char *dest, size_t n, const char *format, ...)
        return (ret);
 } /* int ssnprintf */
 
+char *ssnprintf_alloc (char const *format, ...) /* {{{ */
+{
+       char static_buffer[1024] = "";
+       char *alloc_buffer;
+       size_t alloc_buffer_size;
+       int status;
+       va_list ap;
+
+       /* Try printing into the static buffer. In many cases it will be
+        * sufficiently large and we can simply return a strdup() of this
+        * buffer. */
+       va_start (ap, format);
+       status = vsnprintf (static_buffer, sizeof (static_buffer), format, ap);
+       va_end (ap);
+       if (status < 0)
+               return (NULL);
+
+       /* "status" does not include the null byte. */
+       alloc_buffer_size = (size_t) (status + 1);
+       if (alloc_buffer_size <= sizeof (static_buffer))
+               return (strdup (static_buffer));
+
+       /* Allocate a buffer large enough to hold the string. */
+       alloc_buffer = malloc (alloc_buffer_size);
+       if (alloc_buffer == NULL)
+               return (NULL);
+       memset (alloc_buffer, 0, alloc_buffer_size);
+
+       /* Print again into this new buffer. */
+       va_start (ap, format);
+       status = vsnprintf (alloc_buffer, alloc_buffer_size, format, ap);
+       va_end (ap);
+       if (status < 0)
+       {
+               sfree (alloc_buffer);
+               return (NULL);
+       }
+
+       return (alloc_buffer);
+} /* }}} char *ssnprintf_alloc */
+
 char *sstrdup (const char *s)
 {
        char *r;

diff --git a/src/common.h b/src/common.h
index 7c0d9369cf498db70712958a6d593ccb0d58d3e8..317be8d1579d063cc23338e229abcdede533da84 100644 (file)
--- a/src/common.h
+++ b/src/common.h
@@ -56,7 +56,13 @@ struct rate_to_value_state_s
 typedef struct rate_to_value_state_s rate_to_value_state_t;
 
 char *sstrncpy (char *dest, const char *src, size_t n);
+
+__attribute__ ((format(printf,3,4)))
 int ssnprintf (char *dest, size_t n, const char *format, ...);
+
+__attribute__ ((format(printf,1,2)))
+char *ssnprintf_alloc (char const *format, ...);
+
 char *sstrdup(const char *s);
 void *smalloc(size_t size);
 char *sstrerror (int errnum, char *buf, size_t buflen);