Initial Spring 2016 commit.
This commit is contained in:
Geoffrey Challen
13
userland/bin/sh/Makefile
Normal file
13
userland/bin/sh/Makefile
Normal file
@@ -0,0 +1,13 @@
|
||||
# Makefile for sh
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||||
|
||||
TOP=../../..
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||||
.include "$(TOP)/mk/os161.config.mk"
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PROG=sh
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SRCS=sh.c
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BINDIR=/bin
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HOSTBINDIR=/hostbin
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.include "$(TOP)/mk/os161.prog.mk"
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#.include "$(TOP)/mk/os161.hostprog.mk"
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591
userland/bin/sh/sh.c
Normal file
591
userland/bin/sh/sh.c
Normal file
@@ -0,0 +1,591 @@
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||||
/*
|
||||
* Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
|
||||
* The President and Fellows of Harvard College.
|
||||
*
|
||||
* 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 UNIVERSITY 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 UNIVERSITY 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.
|
||||
*/
|
||||
|
||||
/*
|
||||
* sh - shell
|
||||
*
|
||||
* Usage:
|
||||
* sh
|
||||
* sh -c command
|
||||
*/
|
||||
|
||||
#include <sys/types.h>
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||||
#include <sys/wait.h>
|
||||
#include <assert.h>
|
||||
#include <unistd.h>
|
||||
#include <stdlib.h>
|
||||
#include <stdio.h>
|
||||
#include <string.h>
|
||||
#include <limits.h>
|
||||
#include <errno.h>
|
||||
#include <err.h>
|
||||
|
||||
#ifdef HOST
|
||||
#include "hostcompat.h"
|
||||
#endif
|
||||
|
||||
#ifndef NARG_MAX
|
||||
/* no NARG_MAX on most unixes */
|
||||
#define NARG_MAX 1024
|
||||
#endif
|
||||
|
||||
/* avoid making this unreasonably large; causes problems under dumbvm */
|
||||
#define CMDLINE_MAX 4096
|
||||
|
||||
/* struct to (portably) hold exit info */
|
||||
struct exitinfo {
|
||||
unsigned val:8,
|
||||
signaled:1,
|
||||
stopped:1,
|
||||
coredump:1;
|
||||
};
|
||||
|
||||
/* set to nonzero if __time syscall seems to work */
|
||||
static int timing = 0;
|
||||
|
||||
/* array of backgrounded jobs (allows "foregrounding") */
|
||||
#define MAXBG 128
|
||||
static pid_t bgpids[MAXBG];
|
||||
|
||||
/*
|
||||
* can_bg
|
||||
* just checks for an open slot.
|
||||
*/
|
||||
static
|
||||
int
|
||||
can_bg(void)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; i < MAXBG; i++) {
|
||||
if (bgpids[i] == 0) {
|
||||
return 1;
|
||||
}
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* remember_bg
|
||||
* sticks the pid in an open slot in the background array. note the assert --
|
||||
* better check can_bg before calling this.
|
||||
*/
|
||||
static
|
||||
void
|
||||
remember_bg(pid_t pid)
|
||||
{
|
||||
int i;
|
||||
for (i = 0; i < MAXBG; i++) {
|
||||
if (bgpids[i] == 0) {
|
||||
bgpids[i] = pid;
|
||||
return;
|
||||
}
|
||||
}
|
||||
assert(0);
|
||||
}
|
||||
|
||||
/*
|
||||
* constructor for exitinfo
|
||||
*/
|
||||
static
|
||||
void
|
||||
exitinfo_exit(struct exitinfo *ei, int code)
|
||||
{
|
||||
ei->val = code;
|
||||
ei->signaled = 0;
|
||||
ei->stopped = 0;
|
||||
ei->coredump = 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* readstatus
|
||||
* unpack results from wait
|
||||
*/
|
||||
static
|
||||
void
|
||||
readstatus(int status, struct exitinfo *ei)
|
||||
{
|
||||
if (WIFEXITED(status)) {
|
||||
ei->val = WEXITSTATUS(status);
|
||||
ei->signaled = 0;
|
||||
ei->stopped = 0;
|
||||
ei->coredump = 0;
|
||||
}
|
||||
else if (WIFSIGNALED(status) && WCOREDUMP(status)) {
|
||||
ei->val = WTERMSIG(status);
|
||||
ei->signaled = 1;
|
||||
ei->stopped = 0;
|
||||
ei->coredump = 1;
|
||||
}
|
||||
else if (WIFSIGNALED(status)) {
|
||||
ei->val = WTERMSIG(status);
|
||||
ei->signaled = 1;
|
||||
ei->stopped = 0;
|
||||
ei->coredump = 0;
|
||||
}
|
||||
else if (WIFSTOPPED(status)) {
|
||||
ei->val = WSTOPSIG(status);
|
||||
ei->signaled = 0;
|
||||
ei->stopped = 1;
|
||||
ei->coredump = 0;
|
||||
}
|
||||
else {
|
||||
printf("Invalid status code %d", status);
|
||||
ei->val = status;
|
||||
ei->signaled = 0;
|
||||
ei->stopped = 0;
|
||||
ei->coredump = 0;
|
||||
}
|
||||
|
||||
}
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||||
|
||||
/*
|
||||
* printstatus
|
||||
* print results from wait
|
||||
*/
|
||||
static
|
||||
void
|
||||
printstatus(const struct exitinfo *ei, int printexitzero)
|
||||
{
|
||||
if (ei->signaled && ei->coredump) {
|
||||
printf("Signal %d (core dumped)\n", ei->val);
|
||||
}
|
||||
else if (ei->signaled) {
|
||||
printf("Signal %d\n", ei->val);
|
||||
}
|
||||
else if (ei->stopped) {
|
||||
printf("Stopped on signal %d\n", ei->val);
|
||||
}
|
||||
else if (printexitzero || ei->val != 0) {
|
||||
printf("Exit %d\n", ei->val);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* dowait
|
||||
* just does a waitpid.
|
||||
*/
|
||||
static
|
||||
void
|
||||
dowait(pid_t pid)
|
||||
{
|
||||
struct exitinfo ei;
|
||||
int status;
|
||||
|
||||
if (waitpid(pid, &status, 0) < 0) {
|
||||
warn("pid %d", pid);
|
||||
}
|
||||
else {
|
||||
printf("pid %d: ", pid);
|
||||
readstatus(status, &ei);
|
||||
printstatus(&ei, 1);
|
||||
}
|
||||
}
|
||||
|
||||
#ifdef WNOHANG
|
||||
/*
|
||||
* dowaitpoll
|
||||
* like dowait, but uses WNOHANG. returns true if we got something.
|
||||
*/
|
||||
static
|
||||
int
|
||||
dowaitpoll(pid_t pid)
|
||||
{
|
||||
struct exitinfo ei;
|
||||
pid_t foundpid;
|
||||
int status;
|
||||
|
||||
foundpid = waitpid(pid, &status, WNOHANG);
|
||||
if (foundpid < 0) {
|
||||
warn("pid %d", pid);
|
||||
}
|
||||
else if (foundpid != 0) {
|
||||
printf("pid %d: ", pid);
|
||||
readstatus(status, &ei);
|
||||
printstatus(&ei, 1);
|
||||
return 1;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* waitpoll
|
||||
* poll all background jobs for having exited.
|
||||
*/
|
||||
static
|
||||
void
|
||||
waitpoll(void)
|
||||
{
|
||||
int i;
|
||||
for (i=0; i < MAXBG; i++) {
|
||||
if (bgpids[i] != 0) {
|
||||
if (dowaitpoll(bgpids[i])) {
|
||||
bgpids[i] = 0;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
#endif /* WNOHANG */
|
||||
|
||||
/*
|
||||
* wait
|
||||
* allows the user to "foreground" a process by waiting on it. without ps to
|
||||
* know the pids, this is a little tough to use with an arg, but without an
|
||||
* arg it will wait for all the background jobs.
|
||||
*/
|
||||
static
|
||||
void
|
||||
cmd_wait(int ac, char *av[], struct exitinfo *ei)
|
||||
{
|
||||
int i;
|
||||
pid_t pid;
|
||||
|
||||
if (ac == 2) {
|
||||
pid = atoi(av[1]);
|
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dowait(pid);
|
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for (i = 0; i < MAXBG; i++) {
|
||||
if (bgpids[i]==pid) {
|
||||
bgpids[i] = 0;
|
||||
}
|
||||
}
|
||||
exitinfo_exit(ei, 0);
|
||||
return;
|
||||
}
|
||||
else if (ac == 1) {
|
||||
for (i=0; i < MAXBG; i++) {
|
||||
if (bgpids[i] != 0) {
|
||||
dowait(bgpids[i]);
|
||||
bgpids[i] = 0;
|
||||
}
|
||||
}
|
||||
exitinfo_exit(ei, 0);
|
||||
return;
|
||||
}
|
||||
printf("Usage: wait [pid]\n");
|
||||
exitinfo_exit(ei, 1);
|
||||
}
|
||||
|
||||
/*
|
||||
* chdir
|
||||
* just an interface to the system call. no concept of home directory, so
|
||||
* require the directory.
|
||||
*/
|
||||
static
|
||||
void
|
||||
cmd_chdir(int ac, char *av[], struct exitinfo *ei)
|
||||
{
|
||||
if (ac == 2) {
|
||||
if (chdir(av[1])) {
|
||||
warn("chdir: %s", av[1]);
|
||||
exitinfo_exit(ei, 1);
|
||||
return;
|
||||
}
|
||||
exitinfo_exit(ei, 0);
|
||||
return;
|
||||
}
|
||||
printf("Usage: chdir dir\n");
|
||||
exitinfo_exit(ei, 1);
|
||||
}
|
||||
|
||||
/*
|
||||
* exit
|
||||
* pretty simple. allow the user to choose the exit code if they want,
|
||||
* otherwise default to 0 (success).
|
||||
*/
|
||||
static
|
||||
void
|
||||
cmd_exit(int ac, char *av[], struct exitinfo *ei)
|
||||
{
|
||||
int code;
|
||||
|
||||
if (ac == 1) {
|
||||
code = 0;
|
||||
}
|
||||
else if (ac == 2) {
|
||||
code = atoi(av[1]);
|
||||
}
|
||||
else {
|
||||
printf("Usage: exit [code]\n");
|
||||
exitinfo_exit(ei, 1);
|
||||
return;
|
||||
}
|
||||
|
||||
exit(code);
|
||||
}
|
||||
|
||||
/*
|
||||
* a struct of the builtins associates the builtin name with the function that
|
||||
* executes it. they must all take an argc and argv.
|
||||
*/
|
||||
static struct {
|
||||
const char *name;
|
||||
void (*func)(int, char **, struct exitinfo *);
|
||||
} builtins[] = {
|
||||
{ "cd", cmd_chdir },
|
||||
{ "chdir", cmd_chdir },
|
||||
{ "exit", cmd_exit },
|
||||
{ "wait", cmd_wait },
|
||||
{ NULL, NULL }
|
||||
};
|
||||
|
||||
/*
|
||||
* docommand
|
||||
* tokenizes the command line using strtok. if there aren't any commands,
|
||||
* simply returns. checks to see if it's a builtin, running it if it is.
|
||||
* otherwise, it's a standard command. check for the '&', try to background
|
||||
* the job if possible, otherwise just run it and wait on it.
|
||||
*/
|
||||
static
|
||||
void
|
||||
docommand(char *buf, struct exitinfo *ei)
|
||||
{
|
||||
char *args[NARG_MAX + 1];
|
||||
int nargs, i;
|
||||
char *s;
|
||||
pid_t pid;
|
||||
int status;
|
||||
int bg=0;
|
||||
time_t startsecs, endsecs;
|
||||
unsigned long startnsecs, endnsecs;
|
||||
|
||||
nargs = 0;
|
||||
for (s = strtok(buf, " \t\r\n"); s; s = strtok(NULL, " \t\r\n")) {
|
||||
if (nargs >= NARG_MAX) {
|
||||
printf("%s: Too many arguments "
|
||||
"(exceeds system limit)\n",
|
||||
args[0]);
|
||||
exitinfo_exit(ei, 1);
|
||||
return;
|
||||
}
|
||||
args[nargs++] = s;
|
||||
}
|
||||
args[nargs] = NULL;
|
||||
|
||||
if (nargs==0) {
|
||||
/* empty line */
|
||||
exitinfo_exit(ei, 0);
|
||||
return;
|
||||
}
|
||||
|
||||
for (i=0; builtins[i].name; i++) {
|
||||
if (!strcmp(builtins[i].name, args[0])) {
|
||||
builtins[i].func(nargs, args, ei);
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
/* Not a builtin; run it */
|
||||
|
||||
if (nargs > 0 && !strcmp(args[nargs-1], "&")) {
|
||||
/* background */
|
||||
if (!can_bg()) {
|
||||
printf("%s: Too many background jobs; wait for "
|
||||
"some to finish before starting more\n",
|
||||
args[0]);
|
||||
exitinfo_exit(ei, 1);
|
||||
return;
|
||||
}
|
||||
nargs--;
|
||||
args[nargs] = NULL;
|
||||
bg = 1;
|
||||
}
|
||||
|
||||
if (timing) {
|
||||
__time(&startsecs, &startnsecs);
|
||||
}
|
||||
|
||||
pid = fork();
|
||||
switch (pid) {
|
||||
case -1:
|
||||
/* error */
|
||||
warn("fork");
|
||||
exitinfo_exit(ei, 255);
|
||||
return;
|
||||
case 0:
|
||||
/* child */
|
||||
execvp(args[0], args);
|
||||
warn("%s", args[0]);
|
||||
/*
|
||||
* Use _exit() instead of exit() in the child
|
||||
* process to avoid calling atexit() functions,
|
||||
* which would cause hostcompat (if present) to
|
||||
* reset the tty state and mess up our input
|
||||
* handling.
|
||||
*/
|
||||
_exit(1);
|
||||
default:
|
||||
break;
|
||||
}
|
||||
|
||||
/* parent */
|
||||
if (bg) {
|
||||
/* background this command */
|
||||
remember_bg(pid);
|
||||
printf("[%d] %s ... &\n", pid, args[0]);
|
||||
exitinfo_exit(ei, 0);
|
||||
return;
|
||||
}
|
||||
|
||||
if (waitpid(pid, &status, 0) < 0) {
|
||||
warn("waitpid");
|
||||
exitinfo_exit(ei, 255);
|
||||
}
|
||||
else {
|
||||
readstatus(status, ei);
|
||||
}
|
||||
|
||||
if (timing) {
|
||||
__time(&endsecs, &endnsecs);
|
||||
if (endnsecs < startnsecs) {
|
||||
endnsecs += 1000000000;
|
||||
endsecs--;
|
||||
}
|
||||
endnsecs -= startnsecs;
|
||||
endsecs -= startsecs;
|
||||
warnx("subprocess time: %lu.%09lu seconds",
|
||||
(unsigned long) endsecs, (unsigned long) endnsecs);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* getcmd
|
||||
* pulls valid characters off the console, filling the buffer.
|
||||
* backspace deletes a character, simply by moving the position back.
|
||||
* a newline or carriage return breaks the loop, which terminates
|
||||
* the string and returns.
|
||||
*
|
||||
* if there's an invalid character or a backspace when there's nothing
|
||||
* in the buffer, putchars an alert (bell).
|
||||
*/
|
||||
static
|
||||
void
|
||||
getcmd(char *buf, size_t len)
|
||||
{
|
||||
size_t pos = 0;
|
||||
int done=0, ch;
|
||||
|
||||
/*
|
||||
* In the absence of a <ctype.h>, assume input is 7-bit ASCII.
|
||||
*/
|
||||
|
||||
while (!done) {
|
||||
ch = getchar();
|
||||
if ((ch == '\b' || ch == 127) && pos > 0) {
|
||||
putchar('\b');
|
||||
putchar(' ');
|
||||
putchar('\b');
|
||||
pos--;
|
||||
}
|
||||
else if (ch == '\r' || ch == '\n') {
|
||||
putchar('\r');
|
||||
putchar('\n');
|
||||
done = 1;
|
||||
}
|
||||
else if (ch >= 32 && ch < 127 && pos < len-1) {
|
||||
buf[pos++] = ch;
|
||||
putchar(ch);
|
||||
}
|
||||
else {
|
||||
/* alert (bell) character */
|
||||
putchar('\a');
|
||||
}
|
||||
}
|
||||
buf[pos] = 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* interactive
|
||||
* runs the interactive shell. basically, just infinitely loops, grabbing
|
||||
* commands and running them (and printing the exit status if it's not
|
||||
* success.)
|
||||
*/
|
||||
static
|
||||
void
|
||||
interactive(void)
|
||||
{
|
||||
char buf[CMDLINE_MAX];
|
||||
struct exitinfo ei;
|
||||
|
||||
while (1) {
|
||||
printf("OS/161$ ");
|
||||
getcmd(buf, sizeof(buf));
|
||||
docommand(buf, &ei);
|
||||
printstatus(&ei, 0);
|
||||
#ifdef WNOHANG
|
||||
waitpoll();
|
||||
#endif
|
||||
}
|
||||
}
|
||||
|
||||
static
|
||||
void
|
||||
check_timing(void)
|
||||
{
|
||||
time_t secs;
|
||||
unsigned long nsecs;
|
||||
if (__time(&secs, &nsecs) != -1) {
|
||||
timing = 1;
|
||||
warnx("Timing enabled.");
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* main
|
||||
* if there are no arguments, run interactively, otherwise, run a program
|
||||
* from within the shell, but immediately exit.
|
||||
*/
|
||||
int
|
||||
main(int argc, char *argv[])
|
||||
{
|
||||
#ifdef HOST
|
||||
hostcompat_init(argc, argv);
|
||||
#endif
|
||||
check_timing();
|
||||
|
||||
/*
|
||||
* Allow argc to be 0 in case we're running on a broken kernel,
|
||||
* or one that doesn't set argv when starting the first shell.
|
||||
*/
|
||||
if (argc == 0 || argc == 1) {
|
||||
interactive();
|
||||
}
|
||||
else if (argc == 3 && !strcmp(argv[1], "-c")) {
|
||||
struct exitinfo ei;
|
||||
docommand(argv[2], &ei);
|
||||
printstatus(&ei, 0);
|
||||
if (ei.signaled || ei.stopped || ei.val != 0) {
|
||||
exit(1);
|
||||
}
|
||||
}
|
||||
else {
|
||||
errx(1, "Usage: sh [-c command]");
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
Reference in New Issue
Block a user