NAME

std::ferror - std::ferror

Synopsis

Defined in header <cstdio>
int ferror( std::FILE* stream );

Checks the given stream for errors.

Parameters

stream - the file stream to check

Return value

Nonzero value if the file stream has errors occurred, 0 otherwise

Example

// Run this code

#include <cstdio>
#include <cstdlib>
#include <clocale>
#include <cwchar>

int main(void)
{
const char *fname = std::tmpnam(nullptr);
std::FILE* f = std::fopen(fname, "wb");
std::fputs("\xff\xff\n", f); // not a valid UTF-8 character sequence
std::fclose(f);

std::setlocale(LC_ALL, "en_US.utf8");
f = std::fopen(fname, "rb");
std::wint_t ch;
while ((ch=std::fgetwc(f)) != WEOF) // attempt to read as UTF-8
std::printf("%#x ", ch);

if (std::feof(f))
puts("EOF indicator set");
if (std::ferror(f))
puts("Error indicator set");
}

Output:

Error indicator set

See also

clearerr clears errors
(function)
feof checks for the end-of-file
(function)
fail checks if an error has occurred
(public member function of std::basic_ios<CharT,Traits>)