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Diffstat (limited to 'bin/1sh/eval.c')
| -rw-r--r-- | bin/1sh/eval.c | 1381 |
1 files changed, 1381 insertions, 0 deletions
diff --git a/bin/1sh/eval.c b/bin/1sh/eval.c new file mode 100644 index 00000000..67a40691 --- /dev/null +++ b/bin/1sh/eval.c @@ -0,0 +1,1381 @@ +/*- + * 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 <sys/cdefs.h> +__FBSDID("$FreeBSD: releng/12.1/bin/sh/eval.c 327212 2017-12-26 16:23:18Z jilles $"); + +#include <paths.h> +#include <signal.h> +#include <stdlib.h> +#include <unistd.h> +#include <sys/resource.h> +#include <errno.h> + +/* + * 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 || e == EXEXEC) { + if (in_redirect) { + exitstatus = 2; + 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 && exception != EXEXEC; + 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 || exception == EXEXEC) + exitstatus = 2; + 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 forbit 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; + else if (e != EXEXIT) + exitstatus = 2; + 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 && e != EXEXEC) + || 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; +} |