gui: fix default stat command
[paraslash.git] / stdin.c
1 /*
2 * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18
19 /** \file stdin.c functions that deal with reading from stdin */
20
21 #include "para.h"
22 #include "string.h"
23 #include "list.h"
24 #include "sched.h"
25 #include "fd.h"
26 #include "error.h"
27 #include "stdin.h"
28
29 /**
30 * the pre_select function of the stdin task
31 *
32 * \param s the scheduler this task was registered to
33 * \param t the task structure of the stdin task
34 *
35 * This function is always successful. If there is space left in the
36 * buffer of the stdin task, it adds \p STDIN_FILENO to the read fd set
37 * of \a s.
38 */
39 void stdin_pre_select(struct sched *s, struct task *t)
40 {
41 struct stdin_task *sit = t->private_data;
42 t->ret = 1;
43 sit->check_fd = 0;
44 if (sit->loaded >= sit->bufsize)
45 return;
46 sit->check_fd = 1;
47 para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno);
48 }
49
50 static void stdin_default_event_handler(struct task *t)
51 {
52 PARA_NOTICE_LOG("%p: %s\n", t, PARA_STRERROR(-t->ret));
53 unregister_task(t);
54 }
55
56 /**
57 * the post select function of the stdin task
58 *
59 * \param s the scheduler this task was registered to
60 * \param t the task structure of the stdin task
61 *
62 * This function checks if \p STDIN_FILENO was included by in the read fd set
63 * of \a s during the previous pre_select call. If yes, and \p STDIN_FILENO
64 * appeears to be readable, data is read from stdin into the buffer of the
65 * stdin task.
66 */
67 void stdin_post_select(struct sched *s, struct task *t)
68 {
69 struct stdin_task *sit = t->private_data;
70 ssize_t ret;
71
72 t->ret = 1;
73 if (!sit->check_fd)
74 return;
75 if (!FD_ISSET(STDIN_FILENO, &s->rfds))
76 return;
77 ret = read(STDIN_FILENO, sit->buf + sit->loaded, sit->bufsize - sit->loaded);
78 if (ret < 0)
79 t->ret = -E_STDIN_READ;
80 else if (ret > 0) {
81 sit->loaded += ret;
82 t->ret = ret;
83 } else
84 t->ret = -E_STDIN_EOF;
85 if (t->ret < 0)
86 sit->eof = 1;
87 }
88
89 /**
90 * initialize a stdin task structure with default values
91 *
92 * \param sit the stdin task structure
93 *
94 * This fills in the pre/post select function poinzters of the task structure
95 * given by \a sot. It also sets up a default error handler which unregisters
96 * the task. Moreover, \a loaded and \a eof are set to zero and \a bufsize is
97 * initialized to 16 KB (but no buffer is allocated).
98 */
99 void stdin_set_defaults(struct stdin_task *sit)
100 {
101 sit->bufsize = 16 * 1024,
102 sit->loaded = 0,
103 sit->eof = 0,
104 sit->task.pre_select = stdin_pre_select;
105 sit->task.post_select = stdin_post_select;
106 sit->task.event_handler = stdin_default_event_handler;
107 sit->task.private_data = sit;
108 mark_fd_nonblock(STDIN_FILENO);
109 sprintf(sit->task.status, "stdin reader");
110 }