static List *backq(Node *ifs, Node *n) { int p[2], sp; pid_t pid; List *bq; struct termios t; if (n == NULL) return NULL; if (pipe(p) < 0) { uerror("pipe"); rc_error(NULL); } if (interactive) tcgetattr(0, &t); if ((pid = rc_fork()) == 0) { mvfd(p[1], 1); close(p[0]); redirq = NULL; walk(n, FALSE); exit(getstatus()); } close(p[1]); bq = bqinput(glom(ifs), p[0]); close(p[0]); rc_wait4(pid, &sp, TRUE); if (interactive && WIFSIGNALED(sp)) tcsetattr(0, TCSANOW, &t); statprint(-1, sp); varassign("bqstatus", word(strstatus(sp), NULL), FALSE); sigchk(); return bq; }
extern void assign(List *s1, List *s2, bool stack) { List *val = s2; if (s1 == NULL) rc_error("null variable name"); if (s1->n != NULL) rc_error("multi-word variable name"); if (*s1->w == '\0') rc_error("zero-length variable name"); if (a2u(s1->w) != -1) rc_error("numeric variable name"); if (strchr(s1->w, '=') != NULL) rc_error("'=' in variable name"); if (*s1->w == '*' && s1->w[1] == '\0') val = append(varlookup("0"), s2); /* preserve $0 when * is assigned explicitly */ if (s2 != NULL || stack) { if (dashex) prettyprint_var(2, s1->w, val); varassign(s1->w, val, stack); alias(s1->w, varlookup(s1->w), stack); } else { if (dashex) prettyprint_var(2, s1->w, NULL); varrm(s1->w, stack); } }
static void b_shift(char **av) { int shift = (av[1] == NULL ? 1 : a2u(av[1])); List *s, *dollarzero; if (av[1] != NULL && av[2] != NULL) { arg_count("shift"); return; } if (shift < 0) { badnum(av[1]); return; } s = varlookup("*")->n; dollarzero = varlookup("0"); while (s != NULL && shift != 0) { s = s->n; --shift; } if (s == NULL && shift != 0) { fprint(2, "cannot shift\n"); set(FALSE); } else { varassign("*", append(dollarzero, s), FALSE); set(TRUE); } }
static void update_cwd_var(void) { char b[PATH_MAX+1]; List val; const char* ret = getcwd(b, arraysize(b) - 1); if (ret) { val.w = nprint("%s", b); val.n = NULL; varassign("pwd", &val, FALSE); } }
extern bool walk(Node *n, bool parent) { top: sigchk(); if (n == NULL) { if (!parent) exit(0); set(TRUE); return TRUE; } switch (n->type) { case nArgs: case nBackq: case nConcat: case nCount: case nFlat: case nLappend: case nRedir: case nVar: case nVarsub: case nWord: exec(glob(glom(n)), parent); /* simple command */ break; case nBody: walk(n->u[0].p, TRUE); WALK(n->u[1].p, parent); /* WALK doesn't fall through */ case nNowait: { int pid; if ((pid = rc_fork()) == 0) { #if defined(RC_JOB) && defined(SIGTTOU) && defined(SIGTTIN) && defined(SIGTSTP) setsigdefaults(FALSE); rc_signal(SIGTTOU, SIG_IGN); /* Berkeleyized version: put it in a new pgroup. */ rc_signal(SIGTTIN, SIG_IGN); rc_signal(SIGTSTP, SIG_IGN); setpgid(0, getpid()); #else setsigdefaults(TRUE); /* ignore SIGINT, SIGQUIT, SIGTERM */ #endif mvfd(rc_open("/dev/null", rFrom), 0); walk(n->u[0].p, FALSE); exit(getstatus()); } if (interactive) fprint(2, "%d\n", pid); varassign("apid", word(nprint("%d", pid), NULL), FALSE); redirq = NULL; /* kill pre-redir queue */ break; } case nAndalso: { bool oldcond = cond; cond = TRUE; if (walk(n->u[0].p, TRUE)) { cond = oldcond; WALK(n->u[1].p, parent); } else cond = oldcond; break; } case nOrelse: { bool oldcond = cond; cond = TRUE; if (!walk(n->u[0].p, TRUE)) { cond = oldcond; WALK(n->u[1].p, parent); } else cond = oldcond; break; } case nBang: set(!walk(n->u[0].p, TRUE)); break; case nIf: { bool oldcond = cond; Node *true_cmd = n->u[1].p, *false_cmd = NULL; if (true_cmd != NULL && true_cmd->type == nElse) { false_cmd = true_cmd->u[1].p; true_cmd = true_cmd->u[0].p; } cond = TRUE; if (!walk(n->u[0].p, TRUE)) true_cmd = false_cmd; /* run the else clause */ cond = oldcond; WALK(true_cmd, parent); } case nWhile: { Jbwrap j; Edata jbreak; Estack e1, e2; bool testtrue, oldcond = cond; cond = TRUE; if (!walk(n->u[0].p, TRUE)) { /* prevent spurious breaks inside test */ cond = oldcond; break; } if (sigsetjmp(j.j, 1)) break; jbreak.jb = &j; except(eBreak, jbreak, &e1); do { Edata block; block.b = newblock(); cond = oldcond; except(eArena, block, &e2); walk(n->u[1].p, TRUE); testtrue = walk(n->u[0].p, TRUE); unexcept(); /* eArena */ cond = TRUE; } while (testtrue); cond = oldcond; unexcept(); /* eBreak */ break; } case nForin: { List *l, *var = glom(n->u[0].p); Jbwrap j; Estack e1, e2; Edata jbreak; if (sigsetjmp(j.j, 1)) break; jbreak.jb = &j; except(eBreak, jbreak, &e1); for (l = listcpy(glob(glom(n->u[1].p)), nalloc); l != NULL; l = l->n) { Edata block; assign(var, word(l->w, NULL), FALSE); block.b = newblock(); except(eArena, block, &e2); walk(n->u[2].p, TRUE); unexcept(); /* eArena */ } unexcept(); /* eBreak */ break; } case nSubshell: if (dofork(TRUE)) { setsigdefaults(FALSE); walk(n->u[0].p, FALSE); rc_exit(getstatus()); } break; case nAssign: if (n->u[0].p == NULL) rc_error("null variable name"); assign(glom(n->u[0].p), glob(glom(n->u[1].p)), FALSE); set(TRUE); break; case nPipe: dopipe(n); break; case nNewfn: { List *l = glom(n->u[0].p); if (l == NULL) rc_error("null function name"); while (l != NULL) { if (dashex) prettyprint_fn(2, l->w, n->u[1].p); fnassign(l->w, n->u[1].p); l = l->n; } set(TRUE); break; } case nRmfn: { List *l = glom(n->u[0].p); while (l != NULL) { if (dashex) fprint(2, "fn %S\n", l->w); fnrm(l->w); l = l->n; } set(TRUE); break; } case nDup: redirq = NULL; break; /* Null command */ case nMatch: { List *a = glob(glom(n->u[0].p)), *b = glom(n->u[1].p); if (dashex) fprint(2, (a != NULL && a->n != NULL) ? "~ (%L) %L\n" : "~ %L %L\n", a, " ", b, " "); set(lmatch(a, b)); break; } case nSwitch: { List *v = glom(n->u[0].p); while (1) { do { n = n->u[1].p; if (n == NULL) return istrue(); } while (n->u[0].p == NULL || n->u[0].p->type != nCase); if (lmatch(v, glom(n->u[0].p->u[0].p))) { for (n = n->u[1].p; n != NULL && (n->u[0].p == NULL || n->u[0].p->type != nCase); n = n->u[1].p) walk(n->u[0].p, TRUE); break; } } break; } case nPre: { List *v; if (n->u[0].p->type == nRedir || n->u[0].p->type == nDup) { if (redirq == NULL && !dofork(parent)) /* subshell on first preredir */ break; setsigdefaults(FALSE); qredir(n->u[0].p); if (!haspreredir(n->u[1].p)) doredirs(); /* no more preredirs, empty queue */ walk(n->u[1].p, FALSE); rc_exit(getstatus()); /* NOTREACHED */ } else if (n->u[0].p->type == nAssign) { if (isallpre(n->u[1].p)) { walk(n->u[0].p, TRUE); WALK(n->u[1].p, parent); } else { Estack e; Edata var; v = glom(n->u[0].p->u[0].p); assign(v, glob(glom(n->u[0].p->u[1].p)), TRUE); var.name = v->w; except(eVarstack, var, &e); walk(n->u[1].p, parent); varrm(v->w, TRUE); unexcept(); /* eVarstack */ } } else panic("unexpected node in preredir section of walk"); break; } case nBrace: if (n->u[1].p == NULL) { WALK(n->u[0].p, parent); } else if (dofork(parent)) { setsigdefaults(FALSE); walk(n->u[1].p, TRUE); /* Do redirections */ redirq = NULL; /* Reset redirection queue */ walk(n->u[0].p, FALSE); /* Do commands */ rc_exit(getstatus()); /* NOTREACHED */ } break; case nEpilog: qredir(n->u[0].p); if (n->u[1].p != NULL) { WALK(n->u[1].p, parent); /* Do more redirections. */ } else { doredirs(); /* Okay, we hit the bottom. */ } break; case nNmpipe: rc_error("named pipes cannot be executed as commands"); /* NOTREACHED */ default: panic("unknown node in walk"); /* NOTREACHED */ } return istrue(); }