1 /* ISC license. */
2
3 #include <unistd.h>
4 #include <errno.h>
5 #include <sys/wait.h>
6
7 #include <skalibs/strerr2.h>
8 #include <skalibs/allreadwrite.h>
9 #include <skalibs/djbunix.h>
10 #include <skalibs/exec.h>
11
12 #define USAGE "s6-fghack prog..."
13
main(int argc,char const * const * argv)14 int main (int argc, char const *const *argv)
15 {
16 int p[2] ;
17 int pcoe[2] ;
18 pid_t pid ;
19 char dummy ;
20 PROG = "s6-fghack" ;
21 if (argc < 2) strerr_dieusage(100, USAGE) ;
22 if (pipe(p) < 0) strerr_diefu1sys(111, "create hackpipe") ;
23 if (pipe(pcoe) < 0) strerr_diefu1sys(111, "create coepipe") ;
24
25 switch (pid = fork())
26 {
27 case -1 : strerr_diefu1sys(111, "fork") ;
28 case 0 :
29 {
30 int i = 0 ;
31 close(p[0]) ;
32 close(pcoe[0]) ;
33 if (coe(pcoe[1]) < 0) _exit(111) ;
34 for (; i < 30 ; i++) dup(p[1]) ; /* hack. gcc's warning is justified. */
35 exec(argv+1) ;
36 i = errno ;
37 if (fd_write(pcoe[1], "", 1) < 1) _exit(111) ;
38 _exit(i) ;
39 }
40 }
41
42 close(p[1]) ;
43 close(pcoe[1]) ;
44
45 switch (fd_read(pcoe[0], &dummy, 1))
46 {
47 case -1 : strerr_diefu1sys(111, "read on coepipe") ;
48 case 1 :
49 {
50 int wstat ;
51 if (wait_pid(pid, &wstat) < 0) strerr_diefu1sys(111, "wait_pid") ;
52 errno = WEXITSTATUS(wstat) ;
53 strerr_dieexec(111, argv[1]) ;
54 }
55 }
56
57 fd_close(pcoe[0]) ;
58
59 p[1] = fd_read(p[0], &dummy, 1) ;
60 if (p[1] < 0) strerr_diefu1sys(111, "read on hackpipe") ;
61 if (p[1]) strerr_dief2x(102, argv[1], " wrote on hackpipe") ;
62
63 {
64 int wstat ;
65 if (wait_pid(pid, &wstat) < 0) strerr_diefu1sys(111, "wait_pid") ;
66 if (WIFSIGNALED(wstat)) strerr_dief2x(111, argv[2], " crashed") ;
67 return WEXITSTATUS(wstat) ;
68 }
69 }
70