BBS in a Box 15/BBS in a box XV-2.iso/Files II/Prog/U-Z/UltraShell Demo 1.1.sit/UltraShell™ Demo V1.1/ExampleExternalCommand/ucommand.c

C/C++ Source or Header | 1994-10-26 | 4.5 KB | 273 lines | [TEXT/KAHL]

/* Version C */

/*===========================================================\
|                     UltraShell (tm)                        |
|                                                            |
|                       ucommand.c                           |
|     This module permits external commands to obtain        |
|     command line arguments and to access UltraShell        |
|     files for standard input, output, and error.           |
|                                                            |
|           Copyright (C) 1994 by Zack T. Smith              |
|                                                            |
|     Permission is granted to freely distribute this        |
|    file, so long as the data contained herein is not       |
|                  altered in any way.                       |
\===========================================================*/


#include <stdio.h>
#include <string.h>
#include <Files.h>
#include "ucommand.h"


FILE *shell_stdin;
FILE *shell_stdout;
FILE *shell_stderr;


extern errno;


static bcopy (char *dest, char *src, unsigned long count)
{
    while (count--)
        *dest++ = *src++;
}


static char *strdup (char *str)
{
    char *new;

    new = (char*) malloc (strlen (str) + 1);

    strcpy (new, str);

    return new;
}


static void
p2c (char *dest, char *src)
{
    int len = *src;

    bcopy (dest, src+1, len);
    dest[len] = 0;
}


static void
c2p (unsigned char *dest, char *src)
{
    int len =  strlen (src);

    if (len>255)
    {
        dest[0] = 0;
        return;
    }
    dest[0] = len;
    bcopy ((char*)(dest+1), src, len);
}


static remove_newlines (char *str)
{
    char *tmp;

    tmp = strchr (str, '\n');
    if (tmp) *tmp = 0;
    tmp = strchr (str, '\r');
    if (tmp) *tmp = 0;
}


static int
get_tempdir_path (char *return_path)
{
    FILE *f;
    char path [MAX_PATH_LEN];
    short vol;
    Str31 vol_name;
    long system_folder;
    short oserr;

    if (GetVol (vol_name, &vol))
    {
        /* printf ("cannot get volume information\n"); */
        return CANNOT_FIND_TEMP_DIR;
    }

    p2c (path, (char*) vol_name);
    strcat (path, ":System Folder:UltraShellTempDirLocation");

    f = fopen (path, "r");
    if (!f)
    {
        /* printf ("can't open %s\n", path); */
        return CANNOT_FIND_TEMP_DIR;
    }

    fgets (return_path, MAX_PATH_LEN, f);
    fclose(f);

    remove_newlines (return_path);

    return SUCCESS;
}


static int
setup_stdio (void)
{
    FILE *f;
    char path [MAX_PATH_LEN];
    char tmpdir [MAX_PATH_LEN];

    shell_stdout = NULL;
    shell_stdin = NULL;
    shell_stderr = NULL;

    if (get_tempdir_path (tmpdir))
        return 0;

    strcpy (path, tmpdir);
    strcat (path, "stdin");

    f = fopen (path, "r");
    if (f)
    {
        shell_stdin = f;
    }

    strcpy (path, tmpdir);
    strcat (path, "stdout");

    f = fopen (path, "w");
    if (f)
        shell_stdout = f;

    strcpy (path, tmpdir);
    strcat (path, "stderr");

    f = fopen (path, "w");
    if (f)
        shell_stderr = f;

    return 1;
}


void
shell_exit (short return_value)
{
    FILE *f;
    char path [MAX_PATH_LEN];
    long dummy;

    if (shell_stdin)     fclose (shell_stdin);
    if (shell_stdout)     fclose (shell_stdout);
    if (shell_stderr)     fclose (shell_stderr);

    if (get_tempdir_path (path))
        exit (1);

    strcat (path, "return_value");

    f = fopen (path, "w");
    if (f)
    {
        fprintf (f, "%d\n", return_value);
        fclose (f);
    }

    exit (0);
}


long
ucommand (char **argv, unsigned long max_args)
{
    FILE *argfile;
    char line [500];
    Str255 cwd;
    unsigned long argc;
    unsigned long i;
    char args_file_path [MAX_PATH_LEN];

    if (get_tempdir_path (args_file_path))
    {
        printf ("Can't get the temp dir path\n");
        return 0;
    }

    strcat (args_file_path, "args");

    argfile = fopen (args_file_path, "r");
    if (!argfile)
    {
        printf ("Can't open args file %s\n", args_file_path);
        return 0;
    }

    if (!fgets (line, 499, argfile))
    {
        printf ("Can't read the working directory path from the args file.\n");
        return 0;
    }

    remove_newlines (line);

    if (strlen(line) > 255)
    {
        printf ("The working directory path string is too long (over 255 chars).\n");
        return 0;
    }

    c2p (cwd, line);

    if (HSetVol (cwd, 0, 0L))
    {
        printf ("Cannot change to the working directory specified by the shell.\n");
        return 0;
    }

    if (!fgets (line, 499, argfile))
    {
        printf ("Can't read the argc line from args file.\n");
        return 0;
    }

    if (1 != sscanf (line, "%lu", &argc))
    {
        printf ("Can't read argc value\n");
        return 0;
    }

    if (argc > max_args)
        argc = max_args;

    for (i = 0; i < argc; i++)
    {
        if (!fgets (line, 499, argfile))
            return 0;

        remove_newlines (line);

        argv [i] = strdup (line);
    }

    fclose (argfile);

    if (!setup_stdio ())
        ;

    return argc;
}