ferror(3S)

NAME

ferror(), feof(), clearerr() − stream status inquiries

SYNOPSIS

#include <stdio.h>

int ferror(FILE *stream);

int feof(FILE *stream);

void clearerr(FILE *stream);

DESCRIPTION

ferror() Returns non-zero when an I/O error has previously occurred reading from or writing to the named stream, otherwise zero. Unless cleared by clearerr(), or unless the specific stdio routine so indicates, the error indication lasts until the stream is closed.

feof() Returns non-zero when EOF has previously been detected reading the named input stream, otherwise zero.

clearerr() Resets the error indicator and EOF indicator on the named stream to zero.

WARNINGS

All these routines are implemented both as library functions and as macros. The macro versions, which are used by default, are defined in <stdio.h>. To obtain the library function, either use a #undef to remove the macro definition or, if compiling in ANSI-C mode, enclose the function name in parentheses or use the function address. The following example illustrates each of these methods :

#include <stdio.h>
#undef ferror
    ...
main()
{
int (*find_error()) ();
         ...
return_val=ferror(fd);
         ...
return_val=(feof)(fd1);
         ...
find_error = feof;
};

STANDARDS CONFORMANCE

ferror(): AES, SVID2, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1, ANSI C

clearerr(): AES, SVID2, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1, ANSI C

feof(): AES, SVID2, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1, ANSI C

Hewlett-Packard Company — HP-UX Release 9.0: August 1992

Museum