/*- * Copyright (c) 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Kenneth Almquist. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint #if 0 static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95"; #endif #endif /* not lint */ #include #include #include #include #include #include #include /* * Evaluate a command. */ #include "shell.h" #include "nodes.h" #include "syntax.h" #include "expand.h" #include "parser.h" #include "jobs.h" #include "eval.h" #include "builtins.h" #include "options.h" #include "exec.h" #include "redir.h" #include "input.h" #include "output.h" #include "trap.h" #include "var.h" #include "memalloc.h" #include "error.h" #include "show.h" #include "mystring.h" #ifndef NO_HISTORY #include "myhistedit.h" #endif int evalskip; /* set if we are skipping commands */ int skipcount; /* number of levels to skip */ static int loopnest; /* current loop nesting level */ int funcnest; /* depth of function calls */ static int builtin_flags; /* evalcommand flags for builtins */ char *commandname; struct arglist *cmdenviron; int exitstatus; /* exit status of last command */ int oexitstatus; /* saved exit status */ static void evalloop(union node *, int); static void evalfor(union node *, int); static union node *evalcase(union node *); static void evalsubshell(union node *, int); static void evalredir(union node *, int); static void exphere(union node *, struct arglist *); static void expredir(union node *); static void evalpipe(union node *); static int is_valid_fast_cmdsubst(union node *n); static void evalcommand(union node *, int, struct backcmd *); static void prehash(union node *); /* * Called to reset things after an exception. */ void reseteval(void) { evalskip = 0; loopnest = 0; } /* * The eval command. */ int evalcmd(int argc, char **argv) { char *p; char *concat; char **ap; if (argc > 1) { p = argv[1]; if (argc > 2) { STARTSTACKSTR(concat); ap = argv + 2; for (;;) { STPUTS(p, concat); if ((p = *ap++) == NULL) break; STPUTC(' ', concat); } STPUTC('\0', concat); p = grabstackstr(concat); } evalstring(p, builtin_flags); } else exitstatus = 0; return exitstatus; } /* * Execute a command or commands contained in a string. */ void evalstring(const char *s, int flags) { union node *n; struct stackmark smark; int flags_exit; int any; flags_exit = flags & EV_EXIT; flags &= ~EV_EXIT; any = 0; setstackmark(&smark); setinputstring(s, 1); while ((n = parsecmd(0)) != NEOF) { if (n != NULL && !nflag) { if (flags_exit && preadateof()) evaltree(n, flags | EV_EXIT); else evaltree(n, flags); any = 1; if (evalskip) break; } popstackmark(&smark); setstackmark(&smark); } popfile(); popstackmark(&smark); if (!any) exitstatus = 0; if (flags_exit) exraise(EXEXIT); } /* * Evaluate a parse tree. The value is left in the global variable * exitstatus. */ void evaltree(union node *n, int flags) { int do_etest; union node *next; struct stackmark smark; setstackmark(&smark); do_etest = 0; if (n == NULL) { TRACE(("evaltree(NULL) called\n")); exitstatus = 0; goto out; } do { next = NULL; #ifndef NO_HISTORY displayhist = 1; /* show history substitutions done with fc */ #endif TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type)); switch (n->type) { case NSEMI: evaltree(n->nbinary.ch1, flags & ~EV_EXIT); if (evalskip) goto out; next = n->nbinary.ch2; break; case NAND: evaltree(n->nbinary.ch1, EV_TESTED); if (evalskip || exitstatus != 0) { goto out; } next = n->nbinary.ch2; break; case NOR: evaltree(n->nbinary.ch1, EV_TESTED); if (evalskip || exitstatus == 0) goto out; next = n->nbinary.ch2; break; case NREDIR: evalredir(n, flags); break; case NSUBSHELL: evalsubshell(n, flags); do_etest = !(flags & EV_TESTED); break; case NBACKGND: evalsubshell(n, flags); break; case NIF: { evaltree(n->nif.test, EV_TESTED); if (evalskip) goto out; if (exitstatus == 0) next = n->nif.ifpart; else if (n->nif.elsepart) next = n->nif.elsepart; else exitstatus = 0; break; } case NWHILE: case NUNTIL: evalloop(n, flags & ~EV_EXIT); break; case NFOR: evalfor(n, flags & ~EV_EXIT); break; case NCASE: next = evalcase(n); break; case NCLIST: next = n->nclist.body; break; case NCLISTFALLTHRU: if (n->nclist.body) { evaltree(n->nclist.body, flags & ~EV_EXIT); if (evalskip) goto out; } next = n->nclist.next; break; case NDEFUN: defun(n->narg.text, n->narg.next); exitstatus = 0; break; case NNOT: evaltree(n->nnot.com, EV_TESTED); if (evalskip) goto out; exitstatus = !exitstatus; break; case NPIPE: evalpipe(n); do_etest = !(flags & EV_TESTED); break; case NCMD: evalcommand(n, flags, (struct backcmd *)NULL); do_etest = !(flags & EV_TESTED); break; default: out1fmt("Node type = %d\n", n->type); flushout(&output); break; } n = next; popstackmark(&smark); setstackmark(&smark); } while (n != NULL); out: popstackmark(&smark); if (pendingsig) dotrap(); if (eflag && exitstatus != 0 && do_etest) exitshell(exitstatus); if (flags & EV_EXIT) exraise(EXEXIT); } static void evalloop(union node *n, int flags) { int status; loopnest++; status = 0; for (;;) { if (!evalskip) evaltree(n->nbinary.ch1, EV_TESTED); if (evalskip) { if (evalskip == SKIPCONT && --skipcount <= 0) { evalskip = 0; continue; } if (evalskip == SKIPBREAK && --skipcount <= 0) evalskip = 0; if (evalskip == SKIPRETURN) status = exitstatus; break; } if (n->type == NWHILE) { if (exitstatus != 0) break; } else { if (exitstatus == 0) break; } evaltree(n->nbinary.ch2, flags); status = exitstatus; } loopnest--; exitstatus = status; } static void evalfor(union node *n, int flags) { struct arglist arglist; union node *argp; int i; int status; emptyarglist(&arglist); for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { oexitstatus = exitstatus; expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); } loopnest++; status = 0; for (i = 0; i < arglist.count; i++) { setvar(n->nfor.var, arglist.args[i], 0); evaltree(n->nfor.body, flags); status = exitstatus; if (evalskip) { if (evalskip == SKIPCONT && --skipcount <= 0) { evalskip = 0; continue; } if (evalskip == SKIPBREAK && --skipcount <= 0) evalskip = 0; break; } } loopnest--; exitstatus = status; } /* * Evaluate a case statement, returning the selected tree. * * The exit status needs care to get right. */ static union node * evalcase(union node *n) { union node *cp; union node *patp; struct arglist arglist; emptyarglist(&arglist); oexitstatus = exitstatus; expandarg(n->ncase.expr, &arglist, EXP_TILDE); for (cp = n->ncase.cases ; cp ; cp = cp->nclist.next) { for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { if (casematch(patp, arglist.args[0])) { while (cp->nclist.next && cp->type == NCLISTFALLTHRU && cp->nclist.body == NULL) cp = cp->nclist.next; if (cp->nclist.next && cp->type == NCLISTFALLTHRU) return (cp); if (cp->nclist.body == NULL) exitstatus = 0; return (cp->nclist.body); } } } exitstatus = 0; return (NULL); } /* * Kick off a subshell to evaluate a tree. */ static void evalsubshell(union node *n, int flags) { struct job *jp; int backgnd = (n->type == NBACKGND); oexitstatus = exitstatus; expredir(n->nredir.redirect); if ((!backgnd && flags & EV_EXIT && !have_traps()) || forkshell(jp = makejob(n, 1), n, backgnd) == 0) { if (backgnd) flags &=~ EV_TESTED; redirect(n->nredir.redirect, 0); evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ } else if (! backgnd) { INTOFF; exitstatus = waitforjob(jp, (int *)NULL); INTON; } else exitstatus = 0; } /* * Evaluate a redirected compound command. */ static void evalredir(union node *n, int flags) { struct jmploc jmploc; struct jmploc *savehandler; volatile int in_redirect = 1; oexitstatus = exitstatus; expredir(n->nredir.redirect); savehandler = handler; if (setjmp(jmploc.loc)) { int e; handler = savehandler; e = exception; popredir(); if (e == EXERROR && in_redirect) { FORCEINTON; return; } longjmp(handler->loc, 1); } else { INTOFF; handler = &jmploc; redirect(n->nredir.redirect, REDIR_PUSH); in_redirect = 0; INTON; evaltree(n->nredir.n, flags); } INTOFF; handler = savehandler; popredir(); INTON; } static void exphere(union node *redir, struct arglist *fn) { struct jmploc jmploc; struct jmploc *savehandler; struct localvar *savelocalvars; int need_longjmp = 0; unsigned char saveoptreset; redir->nhere.expdoc = ""; savelocalvars = localvars; localvars = NULL; saveoptreset = shellparam.reset; forcelocal++; savehandler = handler; if (setjmp(jmploc.loc)) need_longjmp = exception != EXERROR; else { handler = &jmploc; expandarg(redir->nhere.doc, fn, 0); redir->nhere.expdoc = fn->args[0]; INTOFF; } handler = savehandler; forcelocal--; poplocalvars(); localvars = savelocalvars; shellparam.reset = saveoptreset; if (need_longjmp) longjmp(handler->loc, 1); INTON; } /* * Compute the names of the files in a redirection list. */ static void expredir(union node *n) { union node *redir; for (redir = n ; redir ; redir = redir->nfile.next) { struct arglist fn; emptyarglist(&fn); switch (redir->type) { case NFROM: case NTO: case NFROMTO: case NAPPEND: case NCLOBBER: expandarg(redir->nfile.fname, &fn, EXP_TILDE); redir->nfile.expfname = fn.args[0]; break; case NFROMFD: case NTOFD: if (redir->ndup.vname) { expandarg(redir->ndup.vname, &fn, EXP_TILDE); fixredir(redir, fn.args[0], 1); } break; case NXHERE: exphere(redir, &fn); break; } } } /* * Evaluate a pipeline. All the processes in the pipeline are children * of the process creating the pipeline. (This differs from some versions * of the shell, which make the last process in a pipeline the parent * of all the rest.) */ static void evalpipe(union node *n) { struct job *jp; struct nodelist *lp; int pipelen; int prevfd; int pip[2]; TRACE(("evalpipe(%p) called\n", (void *)n)); pipelen = 0; for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) pipelen++; INTOFF; jp = makejob(n, pipelen); prevfd = -1; for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { prehash(lp->n); pip[1] = -1; if (lp->next) { if (pipe(pip) < 0) { if (prevfd >= 0) close(prevfd); error("Pipe call failed: %s", strerror(errno)); } } if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { INTON; if (prevfd > 0) { dup2(prevfd, 0); close(prevfd); } if (pip[1] >= 0) { if (!(prevfd >= 0 && pip[0] == 0)) close(pip[0]); if (pip[1] != 1) { dup2(pip[1], 1); close(pip[1]); } } evaltree(lp->n, EV_EXIT); } if (prevfd >= 0) close(prevfd); prevfd = pip[0]; if (pip[1] != -1) close(pip[1]); } INTON; if (n->npipe.backgnd == 0) { INTOFF; exitstatus = waitforjob(jp, (int *)NULL); TRACE(("evalpipe: job done exit status %d\n", exitstatus)); INTON; } else exitstatus = 0; } static int is_valid_fast_cmdsubst(union node *n) { return (n->type == NCMD); } /* * Execute a command inside back quotes. If it's a builtin command, we * want to save its output in a block obtained from malloc. Otherwise * we fork off a subprocess and get the output of the command via a pipe. * Should be called with interrupts off. */ void evalbackcmd(union node *n, struct backcmd *result) { int pip[2]; struct job *jp; struct stackmark smark; struct jmploc jmploc; struct jmploc *savehandler; struct localvar *savelocalvars; unsigned char saveoptreset; result->fd = -1; result->buf = NULL; result->nleft = 0; result->jp = NULL; if (n == NULL) { exitstatus = 0; return; } setstackmark(&smark); exitstatus = oexitstatus; if (is_valid_fast_cmdsubst(n)) { savelocalvars = localvars; localvars = NULL; saveoptreset = shellparam.reset; forcelocal++; savehandler = handler; if (setjmp(jmploc.loc)) { if (exception == EXERROR) /* nothing */; else if (exception != 0) { handler = savehandler; forcelocal--; poplocalvars(); localvars = savelocalvars; shellparam.reset = saveoptreset; longjmp(handler->loc, 1); } } else { handler = &jmploc; evalcommand(n, EV_BACKCMD, result); } handler = savehandler; forcelocal--; poplocalvars(); localvars = savelocalvars; shellparam.reset = saveoptreset; } else { if (pipe(pip) < 0) error("Pipe call failed: %s", strerror(errno)); jp = makejob(n, 1); if (forkshell(jp, n, FORK_NOJOB) == 0) { FORCEINTON; close(pip[0]); if (pip[1] != 1) { dup2(pip[1], 1); close(pip[1]); } evaltree(n, EV_EXIT); } close(pip[1]); result->fd = pip[0]; result->jp = jp; } popstackmark(&smark); TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n", result->fd, result->buf, result->nleft, result->jp)); } static int mustexpandto(const char *argtext, const char *mask) { for (;;) { if (*argtext == CTLQUOTEMARK || *argtext == CTLQUOTEEND) { argtext++; continue; } if (*argtext == CTLESC) argtext++; else if (BASESYNTAX[(int)*argtext] == CCTL) return (0); if (*argtext != *mask) return (0); if (*argtext == '\0') return (1); argtext++; mask++; } } static int isdeclarationcmd(struct narg *arg) { int have_command = 0; if (arg == NULL) return (0); while (mustexpandto(arg->text, "command")) { have_command = 1; arg = &arg->next->narg; if (arg == NULL) return (0); /* * To also allow "command -p" and "command --" as part of * a declaration command, add code here. * We do not do this, as ksh does not do it either and it * is not required by POSIX. */ } return (mustexpandto(arg->text, "export") || mustexpandto(arg->text, "readonly") || (mustexpandto(arg->text, "local") && (have_command || !isfunc("local")))); } static void xtracecommand(struct arglist *varlist, int argc, char **argv) { char sep = 0; const char *text, *p, *ps4; int i; ps4 = expandstr(ps4val()); out2str(ps4 != NULL ? ps4 : ps4val()); for (i = 0; i < varlist->count; i++) { text = varlist->args[i]; if (sep != 0) out2c(' '); p = strchr(text, '='); if (p != NULL) { p++; outbin(text, p - text, out2); out2qstr(p); } else out2qstr(text); sep = ' '; } for (i = 0; i < argc; i++) { text = argv[i]; if (sep != 0) out2c(' '); out2qstr(text); sep = ' '; } out2c('\n'); flushout(&errout); } /* * Check if a builtin can safely be executed in the same process, * even though it should be in a subshell (command substitution). * Note that jobid, jobs, times and trap can show information not * available in a child process; this is deliberate. * The arguments should already have been expanded. */ static int safe_builtin(int idx, int argc, char **argv) { /* Generated from builtins.def. */ if (safe_builtin_always(idx)) return (1); if (idx == EXPORTCMD || idx == TRAPCMD || idx == ULIMITCMD || idx == UMASKCMD) return (argc <= 1 || (argc == 2 && argv[1][0] == '-')); if (idx == SETCMD) return (argc <= 1 || (argc == 2 && (argv[1][0] == '-' || argv[1][0] == '+') && argv[1][1] == 'o' && argv[1][2] == '\0')); return (0); } /* * Execute a simple command. * Note: This may or may not return if (flags & EV_EXIT). */ static void evalcommand(union node *cmd, int flags, struct backcmd *backcmd) { union node *argp; struct arglist arglist; struct arglist varlist; char **argv; int argc; char **envp; int varflag; int mode; int pip[2]; struct cmdentry cmdentry; struct job *jp; struct jmploc jmploc; struct jmploc *savehandler; char *savecmdname; struct shparam saveparam; struct localvar *savelocalvars; struct parsefile *savetopfile; volatile int e; char *lastarg; int signaled; int do_clearcmdentry; const char *path = pathval(); int i; /* First expand the arguments. */ TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags)); emptyarglist(&arglist); emptyarglist(&varlist); varflag = 1; jp = NULL; do_clearcmdentry = 0; oexitstatus = exitstatus; exitstatus = 0; /* Add one slot at the beginning for tryexec(). */ appendarglist(&arglist, nullstr); for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { if (varflag && isassignment(argp->narg.text)) { expandarg(argp, varflag == 1 ? &varlist : &arglist, EXP_VARTILDE); continue; } else if (varflag == 1) varflag = isdeclarationcmd(&argp->narg) ? 2 : 0; expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); } appendarglist(&arglist, nullstr); expredir(cmd->ncmd.redirect); argc = arglist.count - 2; argv = &arglist.args[1]; argv[argc] = NULL; lastarg = NULL; if (iflag && funcnest == 0 && argc > 0) lastarg = argv[argc - 1]; /* Print the command if xflag is set. */ if (xflag) xtracecommand(&varlist, argc, argv); /* Now locate the command. */ if (argc == 0) { /* Variable assignment(s) without command */ cmdentry.cmdtype = CMDBUILTIN; cmdentry.u.index = BLTINCMD; cmdentry.special = 0; } else { static const char PATH[] = "PATH="; int cmd_flags = 0, bltinonly = 0; /* * Modify the command lookup path, if a PATH= assignment * is present */ for (i = 0; i < varlist.count; i++) if (strncmp(varlist.args[i], PATH, sizeof(PATH) - 1) == 0) { path = varlist.args[i] + sizeof(PATH) - 1; /* * On `PATH=... command`, we need to make * sure that the command isn't using the * non-updated hash table of the outer PATH * setting and we need to make sure that * the hash table isn't filled with items * from the temporary setting. * * It would be better to forbid using and * updating the table while this command * runs, by the command finding mechanism * is heavily integrated with hash handling, * so we just delete the hash before and after * the command runs. Partly deleting like * changepatch() does doesn't seem worth the * bookinging effort, since most such runs add * directories in front of the new PATH. */ clearcmdentry(); do_clearcmdentry = 1; } for (;;) { if (bltinonly) { cmdentry.u.index = find_builtin(*argv, &cmdentry.special); if (cmdentry.u.index < 0) { cmdentry.u.index = BLTINCMD; argv--; argc++; break; } } else find_command(argv[0], &cmdentry, cmd_flags, path); /* implement the bltin and command builtins here */ if (cmdentry.cmdtype != CMDBUILTIN) break; if (cmdentry.u.index == BLTINCMD) { if (argc == 1) break; argv++; argc--; bltinonly = 1; } else if (cmdentry.u.index == COMMANDCMD) { if (argc == 1) break; if (!strcmp(argv[1], "-p")) { if (argc == 2) break; if (argv[2][0] == '-') { if (strcmp(argv[2], "--")) break; if (argc == 3) break; argv += 3; argc -= 3; } else { argv += 2; argc -= 2; } path = _PATH_STDPATH; clearcmdentry(); do_clearcmdentry = 1; } else if (!strcmp(argv[1], "--")) { if (argc == 2) break; argv += 2; argc -= 2; } else if (argv[1][0] == '-') break; else { argv++; argc--; } cmd_flags |= DO_NOFUNC; bltinonly = 0; } else break; } /* * Special builtins lose their special properties when * called via 'command'. */ if (cmd_flags & DO_NOFUNC) cmdentry.special = 0; } /* Fork off a child process if necessary. */ if (((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN) && ((flags & EV_EXIT) == 0 || have_traps())) || ((flags & EV_BACKCMD) != 0 && (cmdentry.cmdtype != CMDBUILTIN || !safe_builtin(cmdentry.u.index, argc, argv)))) { jp = makejob(cmd, 1); mode = FORK_FG; if (flags & EV_BACKCMD) { mode = FORK_NOJOB; if (pipe(pip) < 0) error("Pipe call failed: %s", strerror(errno)); } if (cmdentry.cmdtype == CMDNORMAL && cmd->ncmd.redirect == NULL && varlist.count == 0 && (mode == FORK_FG || mode == FORK_NOJOB) && !disvforkset() && !iflag && !mflag) { vforkexecshell(jp, argv, environment(), path, cmdentry.u.index, flags & EV_BACKCMD ? pip : NULL); goto parent; } if (forkshell(jp, cmd, mode) != 0) goto parent; /* at end of routine */ if (flags & EV_BACKCMD) { FORCEINTON; close(pip[0]); if (pip[1] != 1) { dup2(pip[1], 1); close(pip[1]); } flags &= ~EV_BACKCMD; } flags |= EV_EXIT; } /* This is the child process if a fork occurred. */ /* Execute the command. */ if (cmdentry.cmdtype == CMDFUNCTION) { #ifdef DEBUG trputs("Shell function: "); trargs(argv); #endif saveparam = shellparam; shellparam.malloc = 0; shellparam.reset = 1; shellparam.nparam = argc - 1; shellparam.p = argv + 1; shellparam.optp = NULL; shellparam.optnext = NULL; INTOFF; savelocalvars = localvars; localvars = NULL; reffunc(cmdentry.u.func); savehandler = handler; if (setjmp(jmploc.loc)) { popredir(); unreffunc(cmdentry.u.func); poplocalvars(); localvars = savelocalvars; freeparam(&shellparam); shellparam = saveparam; funcnest--; handler = savehandler; longjmp(handler->loc, 1); } handler = &jmploc; funcnest++; redirect(cmd->ncmd.redirect, REDIR_PUSH); INTON; for (i = 0; i < varlist.count; i++) mklocal(varlist.args[i]); exitstatus = oexitstatus; evaltree(getfuncnode(cmdentry.u.func), flags & (EV_TESTED | EV_EXIT)); INTOFF; unreffunc(cmdentry.u.func); poplocalvars(); localvars = savelocalvars; freeparam(&shellparam); shellparam = saveparam; handler = savehandler; funcnest--; popredir(); INTON; if (evalskip == SKIPRETURN) { evalskip = 0; skipcount = 0; } if (jp) exitshell(exitstatus); } else if (cmdentry.cmdtype == CMDBUILTIN) { #ifdef DEBUG trputs("builtin command: "); trargs(argv); #endif mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; if (flags == EV_BACKCMD) { memout.nextc = memout.buf; mode |= REDIR_BACKQ; } savecmdname = commandname; savetopfile = getcurrentfile(); cmdenviron = &varlist; e = -1; savehandler = handler; if (setjmp(jmploc.loc)) { e = exception; if (e == EXINT) exitstatus = SIGINT+128; goto cmddone; } handler = &jmploc; redirect(cmd->ncmd.redirect, mode); outclearerror(out1); /* * If there is no command word, redirection errors should * not be fatal but assignment errors should. */ if (argc == 0) cmdentry.special = 1; listsetvar(cmdenviron, cmdentry.special ? 0 : VNOSET); if (argc > 0) bltinsetlocale(); commandname = argv[0]; argptr = argv + 1; nextopt_optptr = NULL; /* initialize nextopt */ builtin_flags = flags; exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); flushall(); if (outiserror(out1)) { warning("write error on stdout"); if (exitstatus == 0 || exitstatus == 1) exitstatus = 2; } cmddone: if (argc > 0) bltinunsetlocale(); cmdenviron = NULL; out1 = &output; out2 = &errout; freestdout(); handler = savehandler; commandname = savecmdname; if (jp) exitshell(exitstatus); if (flags == EV_BACKCMD) { backcmd->buf = memout.buf; backcmd->nleft = memout.buf != NULL ? memout.nextc - memout.buf : 0; memout.buf = NULL; memout.nextc = NULL; memout.bufend = NULL; memout.bufsize = 64; } if (cmdentry.u.index != EXECCMD) popredir(); if (e != -1) { if (e != EXERROR || cmdentry.special) exraise(e); popfilesupto(savetopfile); if (flags != EV_BACKCMD) FORCEINTON; } } else { #ifdef DEBUG trputs("normal command: "); trargs(argv); #endif redirect(cmd->ncmd.redirect, 0); for (i = 0; i < varlist.count; i++) setvareq(varlist.args[i], VEXPORT|VSTACK); envp = environment(); shellexec(argv, envp, path, cmdentry.u.index); /*NOTREACHED*/ } goto out; parent: /* parent process gets here (if we forked) */ if (mode == FORK_FG) { /* argument to fork */ INTOFF; exitstatus = waitforjob(jp, &signaled); INTON; if (iflag && loopnest > 0 && signaled) { evalskip = SKIPBREAK; skipcount = loopnest; } } else if (mode == FORK_NOJOB) { backcmd->fd = pip[0]; close(pip[1]); backcmd->jp = jp; } out: if (lastarg) setvar("_", lastarg, 0); if (do_clearcmdentry) clearcmdentry(); } /* * Search for a command. This is called before we fork so that the * location of the command will be available in the parent as well as * the child. The check for "goodname" is an overly conservative * check that the name will not be subject to expansion. */ static void prehash(union node *n) { struct cmdentry entry; if (n && n->type == NCMD && n->ncmd.args) if (goodname(n->ncmd.args->narg.text)) find_command(n->ncmd.args->narg.text, &entry, 0, pathval()); } /* * Builtin commands. Builtin commands whose functions are closely * tied to evaluation are implemented here. */ /* * No command given, a bltin command with no arguments, or a bltin command * with an invalid name. */ int bltincmd(int argc, char **argv) { if (argc > 1) { out2fmt_flush("%s: not found\n", argv[1]); return 127; } /* * Preserve exitstatus of a previous possible command substitution * as POSIX mandates */ return exitstatus; } /* * Handle break and continue commands. Break, continue, and return are * all handled by setting the evalskip flag. The evaluation routines * above all check this flag, and if it is set they start skipping * commands rather than executing them. The variable skipcount is * the number of loops to break/continue, or the number of function * levels to return. (The latter is always 1.) It should probably * be an error to break out of more loops than exist, but it isn't * in the standard shell so we don't make it one here. */ int breakcmd(int argc, char **argv) { long n; char *end; if (argc > 1) { /* Allow arbitrarily large numbers. */ n = strtol(argv[1], &end, 10); if (!is_digit(argv[1][0]) || *end != '\0') error("Illegal number: %s", argv[1]); } else n = 1; if (n > loopnest) n = loopnest; if (n > 0) { evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; skipcount = n; } return 0; } /* * The `command' command. */ int commandcmd(int argc __unused, char **argv __unused) { const char *path; int ch; int cmd = -1; path = bltinlookup("PATH", 1); while ((ch = nextopt("pvV")) != '\0') { switch (ch) { case 'p': path = _PATH_STDPATH; break; case 'v': cmd = TYPECMD_SMALLV; break; case 'V': cmd = TYPECMD_BIGV; break; } } if (cmd != -1) { if (*argptr == NULL || argptr[1] != NULL) error("wrong number of arguments"); return typecmd_impl(2, argptr - 1, cmd, path); } if (*argptr != NULL) error("commandcmd bad call"); /* * Do nothing successfully if no command was specified; * ksh also does this. */ return 0; } /* * The return command. */ int returncmd(int argc, char **argv) { int ret = argc > 1 ? number(argv[1]) : oexitstatus; evalskip = SKIPRETURN; skipcount = 1; return ret; } int falsecmd(int argc __unused, char **argv __unused) { return 1; } int truecmd(int argc __unused, char **argv __unused) { return 0; } int execcmd(int argc, char **argv) { int i; /* * Because we have historically not supported any options, * only treat "--" specially. */ if (argc > 1 && strcmp(argv[1], "--") == 0) argc--, argv++; if (argc > 1) { iflag = 0; /* exit on error */ mflag = 0; optschanged(); for (i = 0; i < cmdenviron->count; i++) setvareq(cmdenviron->args[i], VEXPORT|VSTACK); shellexec(argv + 1, environment(), pathval(), 0); } return 0; } int timescmd(int argc __unused, char **argv __unused) { struct rusage ru; long shumins, shsmins, chumins, chsmins; double shusecs, shssecs, chusecs, chssecs; if (getrusage(RUSAGE_SELF, &ru) < 0) return 1; shumins = ru.ru_utime.tv_sec / 60; shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; shsmins = ru.ru_stime.tv_sec / 60; shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; if (getrusage(RUSAGE_CHILDREN, &ru) < 0) return 1; chumins = ru.ru_utime.tv_sec / 60; chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; chsmins = ru.ru_stime.tv_sec / 60; chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); return 0; }