printf_s, wprintf_s
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Header File
stdio.h
Category
Formatted input/output functions
Prototype
int printf_s(const char * restrict format, [, argument, ...]);
int wprintf_s(const wchar_t * restrict format, [, argument, ...]);
Description
Replaces printf, wprintf adding security enhancements.
printf_s is equivalent to printf, wprintf, adding run-time constraints that restrict format and argument from beings null pointers.
Note: For Win32 GUI applications, stdout must be redirected.
Return Value
On success, printf_s returns the number of bytes output, otherwise it returns a negative value.
Example
#include <stdio.h>
#include <string.h>
#define I 555
#define R 5.5
int main(void)
{
int i,j,k,l;
char buf[7];
char *prefix = buf;
char tp[20];
printf_s("prefix 6d 6o 8x 10.2e "
"10.2f\n");
strcpy(prefix,"%");
for (i = 0; i < 2; i++)
{
for (j = 0; j < 2; j++)
for (k = 0; k < 2; k++)
for (l = 0; l < 2; l++)
{
if (i==0) strcat(prefix,"-");
if (j==0) strcat(prefix,"+");
if (k==0) strcat(prefix,"#");
if (l==0) strcat(prefix,"0");
printf_s("%5s |",prefix);
strcpy(tp,prefix);
strcat(tp,"6d |");
printf_s(tp,I);
strcpy(tp,"");
strcpy(tp,prefix);
strcat(tp,"6o |");
printf_s(tp,I);
strcpy(tp,"");
strcpy(tp,prefix);
strcat(tp,"8x |");
printf_s(tp,I);
strcpy(tp,"");
strcpy(tp,prefix);
strcat(tp,"10.2e |");
printf_s(tp,R);
strcpy(tp,prefix);
strcat(tp,"10.2f |");
printf_s(tp,R);
printf_s(" \n");
strcpy(prefix,"%");
}
}
return 0;
}
Portability
| POSIX | Win32 | ANSI C | ANSI C++ | |
|---|---|---|---|---|
|
printf_s |
+ |
+ |
+ |
+ |
|
wprintf_s |
+ |