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sortix--sortix/utils/mxsh.cpp
Jonas 'Sortie' Termansen eb5be61d20 Fix trailing blank lines.
2013-12-17 14:30:23 +01:00

384 lines
8.1 KiB
C++

/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012.
This program is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.
You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>.
mxsh.cpp
A simple and hacky Sortix shell.
*******************************************************************************/
#include <sys/wait.h>
#include <sys/termmode.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <signal.h>
#include <termios.h>
int status = 0;
const char* getenv_safe(const char* name)
{
const char* ret = getenv(name);
return ret ? ret : "";
}
void on_sigint(int /*signum*/)
{
printf("^C\n");
}
void updatepwd()
{
const size_t CWD_SIZE = 512;
char cwd[CWD_SIZE];
const char* wd = getcwd(cwd, CWD_SIZE);
if ( !wd ) { wd = "?"; }
setenv("PWD", wd, 1);
}
void updateenv()
{
char str[128];
struct winsize ws;
if ( tcgetwinsize(0, &ws) == 0 )
{
sprintf(str, "%zu", ws.ws_col);
setenv("COLUMNS", str, 1);
sprintf(str, "%zu", ws.ws_row);
setenv("LINES", str, 1);
}
}
int runcommandline(const char** tokens)
{
int result = 127;
size_t cmdnext = 0;
size_t cmdstart;
size_t cmdend;
bool lastcmd = false;
int pipein = 0;
int pipeout = 1;
int pipeinnext = 0;
char** argv;
size_t cmdlen;
const char* execmode;
const char* outputfile;
pid_t childpid;
bool internal;
int internalresult;
readcmd:
// Collect any pending zombie processes.
while ( 0 < waitpid(-1, NULL, WNOHANG) );
cmdstart = cmdnext;
for ( cmdend = cmdstart; true; cmdend++ )
{
const char* token = tokens[cmdend];
if ( !token ||
strcmp(token, ";") == 0 ||
strcmp(token, "&") == 0 ||
strcmp(token, "|") == 0 ||
strcmp(token, ">") == 0 ||
strcmp(token, ">>") == 0 ||
false )
{
break;
}
}
cmdlen = cmdend - cmdstart;
if ( !cmdlen ) { fprintf(stderr, "expected command\n"); goto out; }
execmode = tokens[cmdend];
if ( !execmode ) { lastcmd = true; execmode = ";"; }
tokens[cmdend] = NULL;
if ( strcmp(execmode, "|") == 0 )
{
int pipes[2];
if ( pipe(pipes) ) { perror("pipe"); goto out; }
if ( pipeout != 1 ) { close(pipeout); } pipeout = pipes[1];
if ( pipeinnext != 0 ) { close(pipeinnext); } pipeinnext = pipes[0];
}
outputfile = NULL;
if ( strcmp(execmode, ">") == 0 || strcmp(execmode, ">>") == 0 )
{
outputfile = tokens[cmdend+1];
if ( !outputfile ) { fprintf(stderr, "expected filename\n"); goto out; }
const char* nexttok = tokens[cmdend+2];
if ( nexttok ) { fprintf(stderr, "too many filenames\n"); goto out; }
}
cmdnext = cmdend + 1;
argv = (char**) (tokens + cmdstart);
internal = false;
internalresult = 0;
if ( strcmp(argv[0], "cd") == 0 )
{
internal = true;
const char* newdir = "/";
if ( argv[1] ) { newdir = argv[1]; }
if ( chdir(newdir) )
{
error(0, errno, "cd: %s", newdir);
internalresult = 1;
}
updatepwd();
}
if ( strcmp(argv[0], "exit") == 0 )
{
int exitcode = argv[1] ? atoi(argv[1]) : 0;
exit(exitcode);
}
if ( strcmp(argv[0], "unset") == 0 )
{
internal = true;
unsetenv(argv[1] ? argv[1] : "");
}
if ( strcmp(argv[0], "clearenv") == 0 )
{
internal = true;
clearenv();
}
childpid = internal ? getpid() : fork();
if ( childpid < 0 ) { perror("fork"); goto out; }
if ( childpid )
{
if ( pipein != 0 ) { close(pipein); pipein = 0; }
if ( pipeout != 1 ) { close(pipeout); pipeout = 1; }
if ( pipeinnext != 0 ) { pipein = pipeinnext; pipeinnext = 0; }
if ( strcmp(execmode, "&") == 0 && !tokens[cmdnext] )
{
result = 0; goto out;
}
if ( strcmp(execmode, "&") == 0 || strcmp(execmode, "|") == 0 )
{
goto readcmd;
}
status = internalresult;
int exitstatus;
if ( !internal && waitpid(childpid, &exitstatus, 0) < 0 )
{
perror("waitpid");
return 127;
}
// TODO: HACK: Most signals can't kill processes yet.
if ( WEXITSTATUS(exitstatus) == 128 + SIGINT )
printf("^C\n");
if ( WTERMSIG(status) == SIGKILL )
printf("Killed\n");
status = WEXITSTATUS(exitstatus);
if ( strcmp(execmode, ";") == 0 && tokens[cmdnext] && !lastcmd )
{
goto readcmd;
}
result = status;
goto out;
}
if ( pipeinnext != 0 ) { close(pipeinnext); }
if ( pipein != 0 )
{
close(0);
dup(pipein);
close(pipein);
}
if ( pipeout != 1 )
{
close(1);
dup(pipeout);
close(pipeout);
}
if ( outputfile )
{
close(1);
int flags = O_CREAT | O_WRONLY | O_APPEND;
if ( strcmp(execmode, ">") == 0 ) { flags |= O_TRUNC; }
if ( open(outputfile, flags, 0666) < 0 )
{
error(127, errno, "%s", outputfile);
}
}
updateenv();
char statusstr[32];
sprintf(statusstr, "%i", status);
setenv("?", statusstr, 1);
for ( char** argp = argv; *argp; argp++ )
{
char* arg = *argp;
if ( arg[0] != '$' ) { continue; }
arg = getenv(arg+1);
if ( !arg ) { arg = (char*) ""; }
*argp = arg;
}
if ( !strcmp(argv[0], "env") )
{
for ( size_t i = 0; i < envlength(); i++ )
{
printf("%s\n", getenvindexed(i));
}
exit(0);
}
execvp(argv[0], argv);
error(127, errno, "%s", argv[0]);
return 127;
out:
if ( pipein != 0 ) { close(pipein); }
if ( pipeout != 1 ) { close(pipeout); }
if ( pipeinnext != 0 ) { close(pipeout); }
return result;
}
void get_and_run_command()
{
unsigned termmode = TERMMODE_UNICODE
| TERMMODE_SIGNAL
| TERMMODE_UTF8
| TERMMODE_LINEBUFFER
| TERMMODE_ECHO;
settermmode(0, termmode);
printf("root@sortix %s # ", getenv_safe("PWD"));
fflush(stdout);
const size_t commandsize = 1024;
char command[commandsize + 1];
size_t commandused = 0;
while (true)
{
char c;
ssize_t bytesread = read(1, &c, sizeof(c));
if ( bytesread < 0 && errno == EINTR )
return;
if ( bytesread < 0 ) { error(64, errno, "read stdin"); }
if ( !bytesread )
{
if ( getppid() == 1 )
printf("\nType exit to shutdown the system.\n");
else
{
printf("exit\n");
exit(status);
}
break;
}
if ( !c ) { continue; }
if ( c == '\n' ) { break; }
if ( commandsize <= commandused ) { continue; }
command[commandused++] = c;
}
command[commandused] = '\0';
if ( command[0] == '\0' ) { return; }
if ( strchr(command, '=') && !strchr(command, ' ') && !strchr(command, '\t') )
{
if ( putenv(strdup(command)) ) { perror("putenv"); status = 1; return; }
status = 0;
return;
}
int argc = 0;
const size_t ARGV_MAX_LENGTH = 2048;
const char* argv[ARGV_MAX_LENGTH];
argv[0] = NULL;
bool lastwasspace = true;
bool escaped = false;
for ( size_t i = 0; i <= commandused; i++ )
{
switch ( command[i] )
{
case '\\':
if ( !escaped )
{
memmove(command + i, command + i + 1, commandused+1 - (i-1));
i--;
commandused--;
escaped = true;
break;
}
case '\0':
case ' ':
case '\t':
case '\n':
if ( !command[i] || !escaped )
{
command[i] = 0;
lastwasspace = true;
break;
}
default:
escaped = false;
if ( lastwasspace )
{
if ( argc == ARGV_MAX_LENGTH )
{
fprintf(stderr, "argv max length of %zu entries hit!\n",
ARGV_MAX_LENGTH);
abort();
}
argv[argc++] = command + i;
}
lastwasspace = false;
}
}
if ( !argv[0] ) { return; }
argv[argc] = NULL;
status = runcommandline(argv);
return;
}
int main(int /*argc*/, char* argv[])
{
signal(SIGINT, on_sigint);
char pidstr[32];
char ppidstr[32];
sprintf(pidstr, "%i", getpid());
sprintf(ppidstr, "%i", getppid());
setenv("SHELL", argv[0], 1);
setenv("$", pidstr, 1);
setenv("PPID", ppidstr, 1);
setenv("?", "0", 1);
updatepwd();
while ( true ) { get_and_run_command(); }
}