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 |
+ |