CODEWITHSUNDEEP
clinuxtr24731
SPB
SPB

Reputation: 4218

sprintf_s was not declared in this scope

I have a C program that uses sprintf_s. It works fine in Windows, but when I compile my code in Linux it gives this error:

sprintf_s was not declared in this scope.

Why does this happen and how can I fix it?

Upvotes: 35

Views: 50208

Answers (6)

rurban
rurban

Reputation: 4131

Look at https://github.com/rurban/safeclib for a implementation of the Annex K functions, like this.

Upvotes: -1

Andrey
Andrey

Reputation: 980

During a porting of my program from Windows to Linux, I wrote following implementation in my own windows.h:

inline int sprintf_s(char* buffer, size_t sizeOfBuffer, const char* format, ...)
{
    va_list ap;
    va_start(ap, format);
    int result = vsnprintf(buffer, sizeOfBuffer, format, ap);
    va_end(ap);
    return result;
}

template<size_t sizeOfBuffer>
inline int sprintf_s(char (&buffer)[sizeOfBuffer], const char* format, ...)
{
    va_list ap;
    va_start(ap, format);
    int result = vsnprintf(buffer, sizeOfBuffer, format, ap);
    va_end(ap);
    return result;
}

Upvotes: 1

Deduplicator
Deduplicator

Reputation: 45654

sprintf_s is only part of Annex K, an optional Annex to the C11 standard:

Annex K

...

K.2 Scope

  1. This annex specifies a series of optional extensions that can be useful in the mitigation of security vulnerabilities in programs, and comprise new functions, macros, and types declared or defined in existing standard headers.

...

K.3.5.3.6 The sprintf_s function

Synopsis 

#define __STDC_WANT_LIB_EXT1__1
#include <stdio.h>
int sprintf_s(char * restrict s, rsize_t n,
const char * restrict format, ...);

(emphasis added)

It never made it into POSIX (or Linux) (and is not missed at all, there are even arguments about its usefulness in the committee).

For better portability, use snprintf which is part of the core standard and provides all the functionality you'll need.

Upvotes: 9

Alberto Soto Ballesteros
Alberto Soto Ballesteros

Reputation: 170

sprintf_s is not part of the standard C library, and you won't be able to use it in Linux.

However, snprintf is standard and should do the same task.

Upvotes: 6

gnclmorais
gnclmorais

Reputation: 4971

sprintf_s is not part of the standard C library, so it is not portable, thus you are not able to use it in Linux. BUT you have snprintf, which is very similar and it should help you to accomplish what you want.

Upvotes: 9

peoro
peoro

Reputation: 26060

It's not standard, you won't find such function on Linux.

Standard function snprintf should have a similar semantics.

Upvotes: 44

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