Guardian Native C Library Calls Reference Manual (G06.29+, H06.08+, J06.03+)

vfscanf(3) Guardian Native C Library Calls Reference Manual
is added automatically.
The results from the conversion are placed in *pointer unless you specify assignment suppres-
sion with an * (asterisk). Assignment suppression provides a way to describe an input field that
is to be skipped. The input field is a string of non-white-space characters. It extends to the next
inappropriate character or until width, if specified, is reached.
The conversion code convcode indicates how to interpret the input field. The corresponding
pointer must usually be of a restricted type. You should not specify the pointer parameter for a
suppressed field.
vfscanf() processing ends either at the end of the input file, the end of the conversion
specifications, or when an input character conflicts with the conversion specifications. If
vfscanf() processing ends with an input character conflict, the conflicting character is not read
from the input stream.
Unless there is a match in the conversion specification, trailing white space (including a newline
character) is not read.
The success of literal matches and suppressed assignments cannot be directly determined. The
vfscanf() function returns the number of successfully matched and assigned input items.
NOTES
This function supports both IEEE Std 754-1985 floating-point and Tandem floating-point values
in the native environment. IEEE values can include NaN and infinity, and the sign of 0.0 (zero)
can be either positive or negative. Refer to the fp_class(3) reference page for a description of
IEEE value classes.
Guardian functions are available to convert between floating-point formats. Refer to the Guar-
dian Programmer’s Guide for a discussion of floating-point conversions.
RETURN VALUES
The vfscanf() function returns the number of successfully matched and assigned input items.
This value can be 0 (zero) if there was an early conflict between an input character and a conver-
sion specification. If the input ends before the first conflict or conversion, EOF (End-of-File) is
returned.
ERRORS
If any of the following conditions occur, the vfscanf() function sets errno to the corresponding
value:
[EAGAIN] The O_NONBLOCK flag is set for the underlying input stream and the process
would be delayed by the read operation.
[EBADF] The file descriptor underlying the input stream is not a valid file descriptor or is
not open for reading.
[EILSEQ] The input stream contains an invalid wide character.
[EINTR] The read operation was interrupted by a signal that was caught and no data was
transferred.
[EINVAL] The function call contains an invalid argument.
[EIO] The call is attempting to read from the process’s controlling terminal and either
the process is ignoring or blocking the SIGTTIN signal or the process group is
orphaned.
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