Guardian Native C Library Calls Reference Manual (G06.28+, H06.04+)

scanf(3) Guardian Native C Library Calls Reference Manual
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
scanf() 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 scanf() 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 conversion
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 scanf() 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.
[ENOMEM] Insufficient memory is available for the operation.
[ENXIO] A request was made to a nonexistent device, or the request was outside the capa-
bilities of the device.
RELATED INFORMATION
Functions: atof(3), atoi(3), fp_class(3), fscanf(3), getc(3), getwc(3), isnan(3), printf(3),
sscanf(3).
STANDARDS CONFORMANCE
The [EILSEQ] and [EINVAL] errno values are extensions to the POSIX standards defined in the
XPG4 Version 2 specification.
The POSIX standards leave some features to the implementing vendor to define. The following
features are affected in the HP implementation:
• A - (dash) character that is neither the first nor last character in a scanset for %[scanset]
conversion indicates a range of values. The value preceding a - (dash) character must be
lexically less than or equal to the value after the - (dash).
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