CRTSCTS wrong in man tcsetattr

CRTSCTS wrong in man tcsetattr

[Karel Kulhavy]

Man tcsetattr in gentoo implicitly states that after
#include <termios.h>
#include <unistd.h>

CRTSCTS constant will be defined. This is however false:
tty.c:38: error: `CRTSCTS' undeclared (first use in this function)

CRTSCTS is defined in bits/termios.h and in asm/termbits.h The question
is what is the correct state of affairs?
1) the manpage should say bits/termios.h instead of termios.h
2) the manpage should say asm/termbits.h instead of termios.h
3) the termios.h should include bits/termios.h or asm/termbits.h
4) the manpage should not mention CRTSCTS at all

CL<

Re: CRTSCTS wrong in man tcsetattr

[linux-os (Dick Johnson)]

On Wed, 12 Apr 2006, Nick Craig-Wood wrote:

> In linux.kernel, you wrote:
>>  Man tcsetattr in gentoo implicitly states that after
>>  #include <termios.h>
>>  #include <unistd.h>
>>
>>  CRTSCTS constant will be defined. This is however false:
>>  tty.c:38: error: `CRTSCTS' undeclared (first use in this function)
>>
>>  CRTSCTS is defined in bits/termios.h and in asm/termbits.h The question
>>  is what is the correct state of affairs?
>>  1) the manpage should say bits/termios.h instead of termios.h
>>  2) the manpage should say asm/termbits.h instead of termios.h
>>  3) the termios.h should include bits/termios.h or asm/termbits.h
>>  4) the manpage should not mention CRTSCTS at all
> 5) there is a bug in your installation
>
> Works for me in Debian testing
>
> cat <<'EOF' > z.c
> #include <termios.h>
> #include <unistd.h>
> #include <stdio.h>
>
> int main(void)
> {
>    printf("0x%08X", CRTSCTS);
>    return 0;
> }
> EOF
> gcc -Wall z.c -o z
> ./z
>
> Gives
>
> 0x80000000
>
> --
> Nick Craig-Wood <nick@craig-wood.com> -- http://www.craig-wood.com/nick
> -

No headers in the /usr/include/bits directory should never be
referenced in user code. /usr/include/termios.h picks up whatever
it needs but it is referenced to the user's environment so the
user could certainly screw it up!

Snipped header:

#ifndef	_TERMIOS_H
#define	_TERMIOS_H	1

#include <features.h>
#ifdef __USE_UNIX98
/* We need `pid_t'.  */
# include <bits/types.h>
# ifndef __pid_t_defined
typedef __pid_t pid_t;
#  define __pid_t_defined
# endif
#endif
__BEGIN_DECLS
#include <bits/termios.h>	<----------- Included here
__END_DECLS
#endif /* termios.h  */


If the user had redefined the C_INCLUDE_PATH to junk, this might
quietly fail, depending upon the gcc version.


Cheers,
Dick Johnson
Penguin : Linux version 2.6.15.4 on an i686 machine (5589.42 BogoMips).
Warning : 98.36% of all statistics are fiction, book release in April.
_
\x1a\x04

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Re: CRTSCTS wrong in man tcsetattr

[Nick Craig-Wood]

In linux.kernel, you wrote:
>  Man tcsetattr in gentoo implicitly states that after
>  #include <termios.h>
>  #include <unistd.h>
> 
>  CRTSCTS constant will be defined. This is however false:
>  tty.c:38: error: `CRTSCTS' undeclared (first use in this function)
> 
>  CRTSCTS is defined in bits/termios.h and in asm/termbits.h The question
>  is what is the correct state of affairs?
>  1) the manpage should say bits/termios.h instead of termios.h
>  2) the manpage should say asm/termbits.h instead of termios.h
>  3) the termios.h should include bits/termios.h or asm/termbits.h
>  4) the manpage should not mention CRTSCTS at all
5) there is a bug in your installation

Works for me in Debian testing

cat <<'EOF' > z.c
#include <termios.h>
#include <unistd.h>
#include <stdio.h>

int main(void)
{
    printf("0x%08X", CRTSCTS);
    return 0;
}
EOF
gcc -Wall z.c -o z
./z

Gives

0x80000000

-- 
Nick Craig-Wood <nick@craig-wood.com> -- http://www.craig-wood.com/nick