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
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
/*
* Copyright (c) 2009 Miek Gieben
* child-tr.c handle child stuff
*/
#include "rdup-tr.h"
extern sig_atomic_t sig;
extern gint opt_verbose;
/* signal.c */
void got_sig(int signal);
/* close all pipes except n1 and n2 (-1 is not needed) */
void
close_pipes(GSList *pipes, int n1, int n2)
{
GSList *p;
int *q;
int j;
for (j = 0, p = g_slist_nth(pipes, 0); p; p = p->next, j++) {
q = p->data;
/* msg("Pipe set %d fds %d %d", j, q[0], q[1]); */
if (j == n1 || j == n2)
continue;
#if 0
if (opt_verbose > 0)
msg("Closing pipe set %d", j);
#endif
close(q[0]);
close(q[1]);
}
}
/* return 0 if all ok, -1 for trouble */
int
wait_pids(GSList *pids, int flags)
{
GSList *p;
int status;
int ret = 0;
if (!pids)
return 0;
for (p = g_slist_nth(pids, 0); p; p = p->next) {
if (sig != 0)
signal_abort(sig);
waitpid(*(pid_t* )(p->data), &status, flags);
if (WIFEXITED(status)) {
#if 0
msg("Child exit %d\n", WEXITSTATUS(status));
#endif
if (WEXITSTATUS(status) != 0)
ret = -1;
}
}
return ret;
}
/* create pipes and childs, return pids */
GSList *
create_childeren(GSList *child, GSList **pipes, int file)
{
GSList *p;
GSList *pids = NULL;
GSList *cpipe = NULL;
char **args;
int *pips;
int childs, j;
pid_t *cpid;
if (!child)
return NULL;
/* create all pipes before forking
* As a parent we read from the last pipe created
* We attach file to the input of the first child
* This eliminates to use of a tmp file
*/
childs = g_slist_length(child);
for (j = 0; j < childs; j++) {
pips = g_malloc(2 * sizeof(int));
if (pipe(pips) == -1) {
msg(_("Failure creating pipes"));
exit(EXIT_FAILURE);
}
cpipe = g_slist_append(cpipe, pips);
}
for (j = 0, p = g_slist_nth(child, 0); p; p = p->next, j++) {
if (sig != 0)
signal_abort(sig);
/* fork, exec child */
args = (char**) p->data;
cpid = g_malloc(sizeof(pid_t));
pips = (g_slist_nth(cpipe, j))->data;
if ( (*cpid = fork()) == -1) {
msg(_("Fork error"));
exit(EXIT_FAILURE);
}
if (*cpid != 0) { /* parent */
/* save the pids */
pids = g_slist_append(pids, cpid);
} else { /* child */
if (j == 0) {
/* dup f to stdin */
if (dup2(file, 0) == -1)
exit(EXIT_FAILURE);
close(pips[0]);
/* pips[1] still alive */
if (dup2(pips[1], 1) == -1)
exit(EXIT_FAILURE);
close_pipes(cpipe, j, -1);
} else {
close(file);
/* close read end */
close(pips[0]);
/* dup write to stdout */
if (dup2(pips[1], 1) == -1)
exit(EXIT_FAILURE);
/* re-use pips for the previous pipe pair */
pips = (g_slist_nth(cpipe, j - 1))->data;
/* dup read to stdin */
if (dup2(pips[0], 0) == -1)
exit(EXIT_FAILURE);
/* and close 1 */
close(pips[1]);
close_pipes(cpipe, j, j - 1);
}
/* finally ... exec */
if ( execvp(args[0], args) == -1)
exit(EXIT_FAILURE);
/* never reached */
exit(EXIT_SUCCESS);
}
}
/* all childeren created, close all pipes except the last one */
close_pipes(cpipe, childs - 1, -1);
/* close write end, we only need to read as parent */
pips = (g_slist_last(cpipe))->data;
close(pips[1]);
*pipes = cpipe;
return pids;
}
|