payloads/libpayload/libc/args.c

   1 /*
   2  *
   3  * Copyright (C) 2008 coresystems GmbH
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 /**
  30  * @file libc/readline.c
  31  * Simple readline implementation
  32  */
  33
  34 #include <libpayload.h>
  35 #include <getopt.h>
  36
  37 /* We don't want to waste malloc on this, so we live with a small
  38  * fixed size array
  39  */
  40 char *string_argv[MAX_ARGS];
  41 int string_argc;
  42
  43 /**
  44  * Take a string and make char *argv[] and int argc from it.
  45  *
  46  * This function allows the user to use getopt on an arbitrary string.
  47  *
  48  * global variables valid after a successful run of string_to_args():
  49  *   string_argc pointer to number of arguments
  50  *   string_argv pointer to argument list.
  51  *
  52  * @param caller to be used as argv[0] (may be NULL to ignore)
  53  * @param string to process
  54  * @return 0 if no error occurred.
  55  */
  56 int string_to_args(char *caller, char *string)
  57 {
  58         int i = 0;
  59
  60         if (caller)
  61                 string_argv[i++] = caller;
  62
  63         if (*string)
  64                 string_argv[i++] = string;
  65
  66         /* Terminate if the string ends */
  67         while (string && *string) {
  68                 /* whitespace occurred? */
  69                 if ((*string == ' ') || (*string == '\t')) {
  70                         /* skip all whitespace (and null it) */
  71                         while (*string == ' ' || *string == '\t')
  72                                 *string++ = 0;
  73                         /* if our ugly static array is big enough, store
  74                          * argument to string_argv[]
  75                          */
  76                         if (i < MAX_ARGS)
  77                                 string_argv[i++] = string;
  78                 }
  79                 string++;
  80         }
  81
  82         /* prevent array from overflowing */
  83         string_argc = (i <= MAX_ARGS) ? i : MAX_ARGS;
  84
  85         /* and return whether there was an overflow */
  86         return (i <= MAX_ARGS) ? 0 : 1;
  87 }