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

Checks the given stream for errors.


[edit] Parameters

stream - the file stream to check

[edit] Return value

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

[edit] Example

#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::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");


Error indicator set

[edit] See also

clears errors
checks for the end-of-file
displays a character string corresponding of the current error to stderr
C documentation for ferror