diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/execline/deps-exe/trap | 2 | ||||
| -rw-r--r-- | src/execline/trap.c | 161 |
2 files changed, 163 insertions, 0 deletions
diff --git a/src/execline/deps-exe/trap b/src/execline/deps-exe/trap new file mode 100644 index 0000000..97021b5 --- /dev/null +++ b/src/execline/deps-exe/trap @@ -0,0 +1,2 @@ +${LIBEXECLINE} +-lskarnet diff --git a/src/execline/trap.c b/src/execline/trap.c new file mode 100644 index 0000000..bfb5733 --- /dev/null +++ b/src/execline/trap.c @@ -0,0 +1,161 @@ +/* ISC license. */ + +#include <sys/types.h> +#include <errno.h> +#include <signal.h> +#include <skalibs/bytestr.h> +#include <skalibs/sgetopt.h> +#include <skalibs/uint.h> +#include <skalibs/nsig.h> +#include <skalibs/sig.h> +#include <skalibs/strerr2.h> +#include <skalibs/tai.h> +#include <skalibs/iopause.h> +#include <skalibs/selfpipe.h> +#include <skalibs/env.h> +#include <skalibs/djbunix.h> +#include <execline/execline.h> + +#define USAGE "trap [ -x ] [ -t timeout ] { signal { cmdline } ... } prog..." +#define dieusage() strerr_dieusage(100, USAGE) ; + +static pid_t pids[NSIG + 2] ; +static char const *const *argvs[NSIG + 1] ; + +static void action (unsigned int i, char const *const *envp) +{ + if (argvs[i]) + { + if (!pids[i]) + { + pids[i] = child_spawn0(argvs[i][0], argvs[i], envp) ; + if (!pids[i]) strerr_diefu2sys(111, "spawn ", argvs[i][0]) ; + } + } + else kill(pids[NSIG+1], i) ; +} + +int main (int argc, char const **argv, char const *const *envp) +{ + tain_t tto ; + int xfersigs = 0 ; + int argc1, spfd ; + unsigned int i = NSIG + 2 ; + PROG = "trap" ; + { + unsigned int t = 0 ; + subgetopt_t l = SUBGETOPT_ZERO ; + for (;;) + { + register int opt = subgetopt_r(argc, argv, "xt:", &l) ; + if (opt == -1) break ; + switch (opt) + { + case 'x' : xfersigs = 1 ; break ; + case 't' : if (!uint0_scan(l.arg, &t)) dieusage() ; break ; + default : dieusage() ; + } + } + argc -= l.ind ; argv += l.ind ; + if (t) tain_from_millisecs(&tto, t) ; + else tto = tain_infinite_relative ; + } + + if (!argc) dieusage() ; + argc1 = el_semicolon(argv) ; + if (!argc1) strerr_dief1x(100, "empty block") ; + if (argc1 >= argc) strerr_dief1x(100, "unterminated block") ; + if (argc1 + 1 == argc) dieusage() ; + argv[argc1] = 0 ; + while (i--) argvs[i] = 0 ; + i = 0 ; + tain_now_g() ; + spfd = selfpipe_init() ; + if (spfd < 0) strerr_diefu1sys(111, "selfpipe_init") ; + + while (i < (unsigned int)argc1) + { + int argc2 ; + unsigned int sig = (unsigned int)sig_number(argv[i] + (case_diffb(argv[i], 3, "sig") ? 0 : 3)) ; + if (!sig && !uint0_scan(argv[i], &sig) && case_diffs(argv[i], "timeout")) + strerr_dief3x(100, "unrecognized", " directive: ", argv[i]) ; + argc2 = el_semicolon(argv + ++i) ; + if (!argc2) + strerr_dief3x(100, "empty", " internal block for directive ", argv[i-1]) ; + if (i + argc2 >= argc1) + strerr_dief3x(100, "unterminated", " internal block for directive ", argv[i-1]) ; + if (argvs[sig]) + strerr_dief3x(100, "duplicate", " directive: ", argv[i-1]) ; + if (sig && selfpipe_trap(sig) < 0) + strerr_diefu2sys(111, "trap ", argv[i-1]) ; + argv[i + argc2] = 0 ; + argvs[sig] = argv + i ; + i += argc2 + 1 ; + } + if (!argvs[SIGCHLD] && selfpipe_trap(SIGCHLD) < 0) + strerr_diefu2sys(111, "trap ", "SIGCHLD") ; + + if (xfersigs) + { + sigset_t full ; + sigfillset(&full) ; + sigdelset(&full, SIGCHLD) ; + for (i = 1 ; i <= NSIG ; i++) + if (!argvs[i] && sigismember(&full, i) > 0 && selfpipe_trap(i) < 0) + { + char fmt[UINT_FMT] ; + fmt[uint_fmt(fmt, i)] = 0 ; + strerr_diefu4sys(111, "auto-", "trap ", "signal ", fmt) ; + } + } + + pids[NSIG+1] = child_spawn0(argv[argc1 + 1], argv + argc1 + 1, envp) ; + if (!pids[NSIG+1]) strerr_diefu2sys(111, "spawn ", argv[argc1 + 1]) ; + + { + iopause_fd x = { .fd = spfd, .events = IOPAUSE_READ } ; + char modif[2 + UINT64_FMT] = "!=" ; + unsigned int envlen = env_len(envp) ; + char const *newenvp[envlen + 2] ; + i = 2 + uint64_fmt(modif + 2, pids[NSIG+1]) ; + modif[i++] = 0 ; + if (!env_merge(newenvp, envlen + 2, envp, envlen, modif, i)) + strerr_diefu1sys(111, "adjust environment") ; + for (;;) + { + tain_t deadline ; + register int r ; + tain_add_g(&deadline, &tto) ; + r = iopause_g(&x, 1, &deadline) ; + if (r < 0) strerr_diefu1sys(111, "iopause") ; + if (!r) action(0, newenvp) ; + else + { + int cont = 1 ; + while (cont) + { + r = selfpipe_read() ; + switch (r) + { + case -1 : strerr_diefu1sys(111, "selfpipe_read") ; + case 0 : cont = 0 ; break ; + case SIGCHLD : + for (;;) + { + int id, wstat ; + id = wait_pids_nohang(pids, NSIG + 2, &wstat) ; + if (id < 0 && errno != ECHILD) + strerr_diefu1sys(111, "wait") ; + if (id <= 0) break ; + pids[id - 1] = 0 ; + if (id == NSIG + 2) return wait_estatus(wstat) ; + } + if (!argvs[SIGCHLD]) break ; + default : + action(r, newenvp) ; + } + } + } + } + } +} |