HP-UX Reference (11i v2 04/09) - 3 Library Functions N-Z (vol 7)

ManualsBrandsHP ManualsSoftwareHP-UX Reference Manuals

251

252

253

254

255

256

257

258

259

260

putc(3S) putc(3S)

[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 neither

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 process.

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

printing 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

applications. New multithreaded applications should 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.