src/core/asprintf.c

   1 #include <stdint.h>
   2 #include <stddef.h>
   3 #include <stdlib.h>
   4 #include <stdio.h>
   5 #include <errno.h>
   6
   7 FILE_LICENCE ( GPL2_OR_LATER );
   8
   9 /**
  10  * Write a formatted string to newly allocated memory.
  11  *
  12  * @v strp              Pointer to hold allocated string
  13  * @v fmt               Format string
  14  * @v args              Arguments corresponding to the format string
  15  * @ret len             Length of formatted string
  16  */
  17 int vasprintf ( char **strp, const char *fmt, va_list args ) {
  18         size_t len;
  19         va_list args_tmp;
  20
  21         /* Calculate length needed for string */
  22         va_copy ( args_tmp, args );
  23         len = ( vsnprintf ( NULL, 0, fmt, args_tmp ) + 1 );
  24         va_end ( args_tmp );
  25
  26         /* Allocate and fill string */
  27         *strp = malloc ( len );
  28         if ( ! *strp )
  29                 return -ENOMEM;
  30         return vsnprintf ( *strp, len, fmt, args );
  31 }
  32
  33 /**
  34  * Write a formatted string to newly allocated memory.
  35  *
  36  * @v strp              Pointer to hold allocated string
  37  * @v fmt               Format string
  38  * @v ...               Arguments corresponding to the format string
  39  * @ret len             Length of formatted string
  40  */
  41 int asprintf ( char **strp, const char *fmt, ... ) {
  42         va_list args;
  43         int len;
  44
  45         va_start ( args, fmt );
  46         len = vasprintf ( strp, fmt, args );
  47         va_end ( args );
  48         return len;
  49 }