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-rw-r--r--bin/sh/eval.c1381
1 files changed, 1381 insertions, 0 deletions
diff --git a/bin/sh/eval.c b/bin/sh/eval.c
new file mode 100644
index 000000000000..4f7559e18487
--- /dev/null
+++ b/bin/sh/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.
+ * 4. 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("$FreeBSD$");
+
+#include <paths.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/resource.h>
+#include <sys/wait.h> /* For WIFSIGNALED(status) */
+#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 strlist *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(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;
+ }
+ 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 (;;) {
+ evaltree(n->nbinary.ch1, EV_TESTED);
+ if (evalskip) {
+skipping: 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;
+ if (evalskip)
+ goto skipping;
+ }
+ loopnest--;
+ exitstatus = status;
+}
+
+
+
+static void
+evalfor(union node *n, int flags)
+{
+ struct arglist arglist;
+ union node *argp;
+ struct strlist *sp;
+ int status;
+
+ arglist.lastp = &arglist.list;
+ for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
+ oexitstatus = exitstatus;
+ expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
+ }
+ *arglist.lastp = NULL;
+
+ loopnest++;
+ status = 0;
+ for (sp = arglist.list ; sp ; sp = sp->next) {
+ setvar(n->nfor.var, sp->text, 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;
+
+ arglist.lastp = &arglist.list;
+ 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.list->text)) {
+ 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;
+ 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;
+
+ redir->nhere.expdoc = nullstr;
+ savelocalvars = localvars;
+ localvars = NULL;
+ 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->list->text;
+ INTOFF;
+ }
+ handler = savehandler;
+ forcelocal--;
+ poplocalvars();
+ localvars = savelocalvars;
+ 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;
+ fn.lastp = &fn.list;
+ switch (redir->type) {
+ case NFROM:
+ case NTO:
+ case NFROMTO:
+ case NAPPEND:
+ case NCLOBBER:
+ expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
+ redir->nfile.expfname = fn.list->text;
+ break;
+ case NFROMFD:
+ case NTOFD:
+ if (redir->ndup.vname) {
+ expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR);
+ fixredir(redir, fn.list->text, 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;
+
+ setstackmark(&smark);
+ result->fd = -1;
+ result->buf = NULL;
+ result->nleft = 0;
+ result->jp = NULL;
+ if (n == NULL) {
+ exitstatus = 0;
+ goto out;
+ }
+ exitstatus = oexitstatus;
+ if (is_valid_fast_cmdsubst(n)) {
+ savelocalvars = localvars;
+ localvars = NULL;
+ forcelocal++;
+ savehandler = handler;
+ if (setjmp(jmploc.loc)) {
+ if (exception == EXERROR || exception == EXEXEC)
+ exitstatus = 2;
+ else if (exception != 0) {
+ handler = savehandler;
+ forcelocal--;
+ poplocalvars();
+ localvars = savelocalvars;
+ longjmp(handler->loc, 1);
+ }
+ } else {
+ handler = &jmploc;
+ evalcommand(n, EV_BACKCMD, result);
+ }
+ handler = savehandler;
+ forcelocal--;
+ poplocalvars();
+ localvars = savelocalvars;
+ } 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;
+ }
+out:
+ 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, struct arglist *arglist)
+{
+ struct strlist *sp;
+ char sep = 0;
+ const char *p, *ps4;
+
+ ps4 = expandstr(ps4val());
+ out2str(ps4 != NULL ? ps4 : ps4val());
+ for (sp = varlist->list ; sp ; sp = sp->next) {
+ if (sep != 0)
+ out2c(' ');
+ p = strchr(sp->text, '=');
+ if (p != NULL) {
+ p++;
+ outbin(sp->text, p - sp->text, out2);
+ out2qstr(p);
+ } else
+ out2qstr(sp->text);
+ sep = ' ';
+ }
+ for (sp = arglist->list ; sp ; sp = sp->next) {
+ if (sep != 0)
+ out2c(' ');
+ /* Disambiguate command looking like assignment. */
+ if (sp == arglist->list &&
+ strchr(sp->text, '=') != NULL &&
+ strchr(sp->text, '\'') == NULL) {
+ out2c('\'');
+ out2str(sp->text);
+ out2c('\'');
+ } else
+ out2qstr(sp->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)
+{
+ if (idx == BLTINCMD || idx == COMMANDCMD || idx == ECHOCMD ||
+ idx == FALSECMD || idx == JOBIDCMD || idx == JOBSCMD ||
+ idx == KILLCMD || idx == PRINTFCMD || idx == PWDCMD ||
+ idx == TESTCMD || idx == TIMESCMD || idx == TRUECMD ||
+ idx == TYPECMD)
+ 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;
+ struct strlist *sp;
+ 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 realstatus;
+ int do_clearcmdentry;
+ const char *path = pathval();
+
+ /* First expand the arguments. */
+ TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags));
+ arglist.lastp = &arglist.list;
+ varlist.lastp = &varlist.list;
+ varflag = 1;
+ jp = NULL;
+ do_clearcmdentry = 0;
+ oexitstatus = exitstatus;
+ exitstatus = 0;
+ 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);
+ }
+ *arglist.lastp = NULL;
+ *varlist.lastp = NULL;
+ expredir(cmd->ncmd.redirect);
+ argc = 0;
+ for (sp = arglist.list ; sp ; sp = sp->next)
+ argc++;
+ /* Add one slot at the beginning for tryexec(). */
+ argv = stalloc(sizeof (char *) * (argc + 2));
+ argv++;
+
+ for (sp = arglist.list ; sp ; sp = sp->next) {
+ TRACE(("evalcommand arg: %s\n", sp->text));
+ *argv++ = sp->text;
+ }
+ *argv = NULL;
+ lastarg = NULL;
+ if (iflag && funcnest == 0 && argc > 0)
+ lastarg = argv[-1];
+ argv -= argc;
+
+ /* Print the command if xflag is set. */
+ if (xflag)
+ xtracecommand(&varlist, &arglist);
+
+ /* 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 (sp = varlist.list ; sp ; sp = sp->next)
+ if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) {
+ path = sp->text + 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.list == NULL &&
+ (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.optnext = NULL;
+ INTOFF;
+ savelocalvars = localvars;
+ localvars = NULL;
+ reffunc(cmdentry.u.func);
+ savehandler = handler;
+ if (setjmp(jmploc.loc)) {
+ freeparam(&shellparam);
+ shellparam = saveparam;
+ popredir();
+ unreffunc(cmdentry.u.func);
+ poplocalvars();
+ localvars = savelocalvars;
+ funcnest--;
+ handler = savehandler;
+ longjmp(handler->loc, 1);
+ }
+ handler = &jmploc;
+ funcnest++;
+ redirect(cmd->ncmd.redirect, REDIR_PUSH);
+ INTON;
+ for (sp = varlist.list ; sp ; sp = sp->next)
+ mklocal(sp->text);
+ 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.nleft = 0;
+ memout.nextc = memout.buf;
+ memout.bufsize = 64;
+ mode |= REDIR_BACKQ;
+ }
+ savecmdname = commandname;
+ savetopfile = getcurrentfile();
+ cmdenviron = varlist.list;
+ 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.nextc - memout.buf;
+ memout.buf = NULL;
+ }
+ 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 (sp = varlist.list ; sp ; sp = sp->next)
+ setvareq(sp->text, 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, &realstatus);
+ INTON;
+ if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) {
+ 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 redirection
+ * 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)
+{
+ int n = argc > 1 ? number(argv[1]) : 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)
+{
+ /*
+ * Because we have historically not supported any options,
+ * only treat "--" specially.
+ */
+ if (argc > 1 && strcmp(argv[1], "--") == 0)
+ argc--, argv++;
+ if (argc > 1) {
+ struct strlist *sp;
+
+ iflag = 0; /* exit on error */
+ mflag = 0;
+ optschanged();
+ for (sp = cmdenviron; sp ; sp = sp->next)
+ setvareq(sp->text, 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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 06:29:29 +0000