NetBSD/bin/sh/main.c
kre e3847ee4a9 PR standards/42829
Implement parameter and arithmetic expansion of $ENV
before using it as the name of a file from which to
read startup commands for the shell.   This continues
to happen for all interactive shells, and non-interactive
shells for which the posix option is not set (-o posix).

On any actual error, or if an attempt is made to use
command substitution, then the value of ENV is used
unchanged as the file name.

The expansion complies with POSIX XCU 2.5.3, though that
only requires parameter expansion - arithmetic expansion
is an extension (but for us, it is much easier to do, than
not to do, and it allows some weird stuff, if you're so
inclined....)   Note that there is no ~ expansion (use $HOME).
2018-12-11 13:31:20 +00:00

393 lines
8.3 KiB
C

/* $NetBSD: main.c,v 1.79 2018/12/11 13:31:20 kre Exp $ */
/*-
* Copyright (c) 1991, 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.
*/
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1991, 1993\
The Regents of the University of California. All rights reserved.");
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)main.c 8.7 (Berkeley) 7/19/95";
#else
__RCSID("$NetBSD: main.c,v 1.79 2018/12/11 13:31:20 kre Exp $");
#endif
#endif /* not lint */
#include <errno.h>
#include <stdio.h>
#include <signal.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdlib.h>
#include <locale.h>
#include <fcntl.h>
#include "shell.h"
#include "main.h"
#include "mail.h"
#include "options.h"
#include "builtins.h"
#include "output.h"
#include "parser.h"
#include "nodes.h"
#include "expand.h"
#include "eval.h"
#include "jobs.h"
#include "input.h"
#include "trap.h"
#include "var.h"
#include "show.h"
#include "memalloc.h"
#include "error.h"
#include "init.h"
#include "mystring.h"
#include "exec.h"
#include "cd.h"
#include "redir.h"
#define PROFILE 0
int rootpid;
int rootshell;
struct jmploc main_handler;
int max_user_fd;
#if PROFILE
short profile_buf[16384];
extern int etext();
#endif
STATIC void read_profile(const char *);
/*
* Main routine. We initialize things, parse the arguments, execute
* profiles if we're a login shell, and then call cmdloop to execute
* commands. The setjmp call sets up the location to jump to when an
* exception occurs. When an exception occurs the variable "state"
* is used to figure out how far we had gotten.
*/
int
main(int argc, char **argv)
{
struct stackmark smark;
volatile int state;
char *shinit;
uid_t uid;
gid_t gid;
uid = getuid();
gid = getgid();
max_user_fd = fcntl(0, F_MAXFD);
if (max_user_fd < 2)
max_user_fd = 2;
setlocale(LC_ALL, "");
posix = getenv("POSIXLY_CORRECT") != NULL;
#if PROFILE
monitor(4, etext, profile_buf, sizeof profile_buf, 50);
#endif
state = 0;
if (setjmp(main_handler.loc)) {
/*
* When a shell procedure is executed, we raise the
* exception EXSHELLPROC to clean up before executing
* the shell procedure.
*/
switch (exception) {
case EXSHELLPROC:
rootpid = getpid();
rootshell = 1;
minusc = NULL;
state = 3;
break;
case EXEXEC:
exitstatus = exerrno;
break;
case EXERROR:
exitstatus = 2;
break;
default:
break;
}
if (exception != EXSHELLPROC) {
if (state == 0 || iflag == 0 || ! rootshell ||
exception == EXEXIT)
exitshell(exitstatus);
}
reset();
if (exception == EXINT) {
out2c('\n');
flushout(&errout);
}
popstackmark(&smark);
FORCEINTON; /* enable interrupts */
if (state == 1)
goto state1;
else if (state == 2)
goto state2;
else if (state == 3)
goto state3;
else
goto state4;
}
handler = &main_handler;
#ifdef DEBUG
#if DEBUG >= 2
debug = 1; /* this may be reset by procargs() later */
#endif
opentrace();
trputs("Shell args: "); trargs(argv);
#if DEBUG >= 3
set_debug(((DEBUG)==3 ? "_@" : "++"), 1);
#endif
#endif
rootpid = getpid();
rootshell = 1;
init();
initpwd();
setstackmark(&smark);
procargs(argc, argv);
/*
* Limit bogus system(3) or popen(3) calls in setuid binaries,
* by requiring the -p flag
*/
if (!pflag && (uid != geteuid() || gid != getegid())) {
setuid(uid);
setgid(gid);
/* PS1 might need to be changed accordingly. */
choose_ps1();
}
if (argv[0] && argv[0][0] == '-') {
state = 1;
read_profile("/etc/profile");
state1:
state = 2;
read_profile(".profile");
}
state2:
state = 3;
if ((iflag || !posix) &&
getuid() == geteuid() && getgid() == getegid()) {
struct stackmark env_smark;
setstackmark(&env_smark);
if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
state = 3;
read_profile(expandenv(shinit));
}
popstackmark(&env_smark);
}
state3:
state = 4;
line_number = 1; /* undo anything from profile files */
if (sflag == 0 || minusc) {
static int sigs[] = {
SIGINT, SIGQUIT, SIGHUP,
#ifdef SIGTSTP
SIGTSTP,
#endif
SIGPIPE
};
#define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
size_t i;
for (i = 0; i < SIGSSIZE; i++)
setsignal(sigs[i], 0);
}
if (minusc)
evalstring(minusc, sflag ? 0 : EV_EXIT);
if (sflag || minusc == NULL) {
state4: /* XXX ??? - why isn't this before the "if" statement */
cmdloop(1);
}
#if PROFILE
monitor(0);
#endif
exitshell(exitstatus);
/* NOTREACHED */
}
/*
* Read and execute commands. "Top" is nonzero for the top level command
* loop; it turns on prompting if the shell is interactive.
*/
void
cmdloop(int top)
{
union node *n;
struct stackmark smark;
int inter;
int numeof = 0;
enum skipstate skip;
CTRACE(DBG_ALWAYS, ("cmdloop(%d) called\n", top));
setstackmark(&smark);
for (;;) {
if (pendingsigs)
dotrap();
inter = 0;
if (iflag == 1 && top) {
inter = 1;
showjobs(out2, SHOW_CHANGED);
chkmail(0);
flushout(&errout);
nflag = 0;
}
n = parsecmd(inter);
VXTRACE(DBG_PARSE|DBG_EVAL|DBG_CMDS,("cmdloop: "),showtree(n));
if (n == NEOF) {
if (!top || numeof >= 50)
break;
if (nflag)
break;
if (!stoppedjobs()) {
if (!iflag || !Iflag)
break;
out2str("\nUse \"exit\" to leave shell.\n");
}
numeof++;
} else if (n != NULL && nflag == 0) {
job_warning = (job_warning == 2) ? 1 : 0;
numeof = 0;
evaltree(n, 0);
}
rststackmark(&smark);
/*
* Any SKIP* can occur here! SKIP(FUNC|BREAK|CONT) occur when
* a dotcmd is in a loop or a function body and appropriate
* built-ins occurs in file scope in the sourced file. Values
* other than SKIPFILE are reset by the appropriate eval*()
* that contained the dotcmd() call.
*/
skip = current_skipstate();
if (skip != SKIPNONE) {
if (skip == SKIPFILE)
stop_skipping();
break;
}
}
popstackmark(&smark);
}
/*
* Read /etc/profile or .profile. Return on error.
*/
STATIC void
read_profile(const char *name)
{
int fd;
int xflag_set = 0;
int vflag_set = 0;
if (*name == '\0')
return;
INTOFF;
if ((fd = open(name, O_RDONLY)) >= 0)
setinputfd(fd, 1);
INTON;
if (fd < 0)
return;
/* -q turns off -x and -v just when executing init files */
if (qflag) {
if (xflag)
xflag = 0, xflag_set = 1;
if (vflag)
vflag = 0, vflag_set = 1;
}
cmdloop(0);
if (qflag) {
if (xflag_set)
xflag = 1;
if (vflag_set)
vflag = 1;
}
popfile();
}
/*
* Read a file containing shell functions.
*/
void
readcmdfile(char *name)
{
int fd;
INTOFF;
if ((fd = open(name, O_RDONLY)) >= 0)
setinputfd(fd, 1);
else
error("Can't open %s", name);
INTON;
cmdloop(0);
popfile();
}
int
exitcmd(int argc, char **argv)
{
if (stoppedjobs())
return 0;
if (argc > 1)
exitshell(number(argv[1]));
else
exitshell_savedstatus();
/* NOTREACHED */
}