HP-UX Reference (11i v1 00/12) - 3 Library Functions N-Z (vol 7)

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STANDARD Printed by: Nora Chuang [nchuang] STANDARD

/build/1111/BRICK/man3/nan.3m

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putc(3S) putc(3S)

[EFBIG] An attempt was made to write to a ﬁle that exceeds the process’s ﬁle size limit or the

maximum ﬁle size (see ulimit(2)).

[EINTR] A signal was caught during the write() system call.

[EIO] A physical I/O error has occurred, or the process is in a background process group and

is attempting to write to its controlling terminal, TOSTOP is set, the process is nei-

ther ignoring nor blocking the SIGTTOU signal, and the process group of the process

is orphaned.

[ENOSPC] There was no free space remaining on the device containing the ﬁle.

[EPIPE] An attempt is made to write to a pipe or FIFO that is not open for reading by any pro-

cess. A SIGPIPE signal is also sent to the process.

Additional errno values can be set by the underlying write() function (see write(2)).

WARNINGS

The putc() and putchar() routines are implemented as both library functions and 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 putc

...

main()

{

int (*put_char()) ();

...

return_val=putc(c,fd);

...

return_val=(putc)(c,fd1);

...

put_char = putchar;

};

Line buffering may cause confusion or malfunctioning of programs that use standard

I/O routines but use

read() themselves to read from standard input. When a large amount of computation is done after print-

ing part of a line on an output terminal, it is necessary to fflush() (see fclose(3S)) the standard output

before beginning the computation.

The macro version of

putc() incorrectly treats the argument stream with side effects. In particular, the

following call may not work as expected:

putc(c, *f++);

The function version of putc() or fputc() should be used instead.

Because of possible differences in word length and byte ordering, ﬁles written using putw() are machine-

dependent, and may not be readable by getw() on a different processor.

putw_unlocked() is an obsolescent interface supported only for compatibility with existing DCE appli-

cations. New multithreaded applicationsshould use

putc(), putchar() and putw().

Reentrant Interfaces

_REENTRANT is deﬁned, the locked versions of the library functions for putc() and putchar()

are

used by default.