Merge remote-tracking branch 'github/pr/387'

[collectd.git] / src / common.c

diff --git a/src/common.c b/src/common.c
index c41c4fe629dd14685e543964d9a7c05b7d8f399b..161b4d67fc063d693b1f319e016687cea4ae639d 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;
@@ -1220,18 +1261,25 @@ int walk_directory (const char *dir, dirwalk_callback_f callback,
        return (0);
 }
 
-int read_file_contents (const char *filename, char *buf, int bufsize)
+ssize_t read_file_contents (const char *filename, char *buf, size_t bufsize)
 {
        FILE *fh;
-       int n;
+       ssize_t ret;
 
-       if ((fh = fopen (filename, "r")) == NULL)
-               return -1;
+       fh = fopen (filename, "r");
+       if (fh == NULL)
+               return (-1);
 
-       n = fread(buf, 1, bufsize, fh);
-       fclose(fh);
+       ret = (ssize_t) fread (buf, 1, bufsize, fh);
+       if ((ret == 0) && (ferror (fh) != 0))
+       {
+               ERROR ("read_file_contents: Reading file \"%s\" failed.",
+                               filename);
+               ret = -1;
+       }
 
-       return n;
+       fclose(fh);
+       return (ret);
 }
 
 counter_t counter_diff (counter_t old_value, counter_t new_value)