1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
#ifndef lint
static char SccsId[] = "%W% %G%";
#endif
/* Module: ctrlpipe.c (Control Pipe Device)
* Purpose: Open a pipe device for IO
* Subroutine: open_pipe() returns: int
* Subroutine: close_pipe() returns: void
* Subroutine: flush_pipe() returns: void
* Copyright: 1989 Smithsonian Astrophysical Observatory
* You may do anything you like with this file except remove
* this copyright. The Smithsonian Astrophysical Observatory
* makes no representations about the suitability of this
* software for any purpose. It is provided "as is" without
* express or implied warranty.
* Modified: {0} Michael VanHilst initial version 25 May 1989
* {1} MVH simplified code for modular strategy 10 March 1990
* {n} <who> -- <does what> -- <when>
*/
#ifndef VMS
#include <stdio.h> /* define stderr, FILE, NULL, etc */
/*
* Subroutine: open_pipe
* Purpose: Open a channel on a named device for pipe I/O
* Returns: Channel number on success (0-64) else -1.
* Note: select_mask and mask_size are augmented, not initialized
*/
int open_pipe ( device_name, write_flag, flush_flag )
char *device_name; /* i: name of pipe device to open */
int write_flag; /* i: >0: write only, <=0: read */
int flush_flag; /* i: 1=flush, 0=don't flush */
{
int ipc; /* o: channel of new pipe connection */
int open_disk();
void fcntl_disk(), flush_disk(), close_disk();
if( write_flag > 0 ) {
int datain;
/* open file to read (don't block) */
if( (datain = open_disk(device_name, -1, 1)) == -1 )
return( -1 );
/* open same file to write (don't block) */
if( (ipc = open_disk(device_name, 1, 1)) == -1 ) {
close_disk(datain, device_name);
return( -1 );
}
/* now enable blocking and close the reading connection */
fcntl_disk(ipc, 1, 0, device_name);
close_disk(datain, device_name);
} else {
/* open the device READ-WRITE, don't block - time_out on failure */
if( (ipc = open_disk(device_name, 0, 1)) == -1 )
return( -1 );
if( flush_flag )
/* if reading, flush old input, if any, with non-blocking reads */
flush_disk(ipc, device_name);
/* from now on block on read or write */
fcntl_disk(ipc, -1, 0, device_name);
}
return( ipc );
}
/*
* Subroutine: close_pipe
* Purpose: Close pipe connection
*/
void close_pipe ( ipc, device_name )
int ipc; /* i: channel number of open pipe */
char *device_name; /* i: name of pipe device */
{
void close_disk();
close_disk(ipc, device_name);
}
/*
* Subroutine: flush_pipe
* Purpose: Suck all bytes out of a pipe open for reading
*/
void flush_pipe ( ipc, filename )
int ipc;
char *filename;
{
void flush_disk();
flush_disk(ipc, filename);
}
#endif
|
