{{keywords>wiki library source code example reference}}
====== fprintf ======

<code c>
     int fprintf(FILE *stream, const char *format, ...);
</code>

Converts (according to format format) and writes output to stream stream. Number of characters written, or negative value on error, is returned.\\
\\
optional flag:\\
\\
-  left adjust\\
+  always sign\\
0  zero pad\\
#  Alternate form: for conversion character o, first digit will be zero, for [xX], prefix 0x or 0X to non-zero value, for [eEfgG], always decimal point, for [gG] trailing zeros not removed. \\
\\
optional minimum width: if specified as *, value taken from next argument (which must be int).\\
optional . (separating width from precision)\\
optional precision: for conversion character s, maximum characters to be printed from the string, for [eEf], digits after decimal point, for [gG], significant digits, for an integer, minimum number of digits to be printed. If specified as *, value taken from next argument (which must be int).\\
\\
optional length modifier:\\

h  short or unsigned short\\
l  long or unsigned long\\
L  long double\\

conversion character:\\

d,i   int argument, printed in signed decimal notation\\
o     int argument, printed in unsigned octal notation\\
x,X   int argument, printed in unsigned hexadecimal notation\\
u     int argument, printed in unsigned decimal notation\\
c     int argument, printed as single character\\
s     char* argument\\
f     double argument, printed with format [-]mmm.ddd\\
e,E   double argument, printed with format [-]m.dddddd(e|E)(+|-)xx\\
g,G   double argument\\
p     void* argument, printed as pointer\\
n     int* argument : the number of characters written to this point is written into argument\\
%     no argument; prints %\\



===== C Sourcecode Example =====
<code c>
/* 
 * fprintf example code
 * http://code-reference.com/c/stdio.h/fprintf 
 */


#include <stdio.h> /* including standard library */
//#include <windows.h> /* uncomment this for Windows */

#define MAX 60

int main ( void )
{
   FILE * stream;
   char string[MAX];
   char c;

   sprintf(string,"This string will be cut here - This will not be shown");

   stream = fopen ("test.txt","w");
   fprintf (stream, "%-8.28s ",string); // -8 is minimun and after the . (in this case 28) is maximum chars
   
   freopen("test.txt", "r", stream);
   while((c = fgetc(stream) ) != EOF) {
      printf("%c", c );
      }
   
   printf("\n");
   fclose (stream);
   return 0;
}

</code>

==== fprintf output example ====
    output:./fprintf 
    This string will be cut here