usr/src/lib/krb5/ss/parse.c

   1 /*
   2  * Copyright 1987, 1988 by MIT Student Information Processing Board
   3  *
   4  * For copyright info, see copyright.h.
   5  */
   6
   7 /*
   8  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
   9  * Use is subject to license terms.
  10  */
  11
  12 #include "ss_internal.h"
  13 #include "copyright.h"
  14 #include <errno.h>
  15
  16 enum parse_mode { WHITESPACE, TOKEN, QUOTED_STRING };
  17
  18
  19 /*
  20  * Solaris Kerberos:
  21  * ss_parse has been modified slightly from the original in two ways.
  22  * 1) A new parameter "quiet" has been added which is used to silence
  23  *    error or warning messages.
  24  * 2) ss_parse now returns an error status instead of argv - this is to
  25  *    allow an error to be distinguished from no tokens when parsing an empty
  26  *    string.
  27  * Both of these changes allow ss_parse to be used during tab-completion.
  28  */
  29
  30 /*
  31  * parse(line_ptr, argc_ptr)
  32  *
  33  * Function:
  34  *      Parses line, dividing at whitespace, into tokens, returns
  35  *      the "argc" and "argv" values.
  36  * Arguments:
  37  *      line_ptr (char *)
  38  *              Pointer to text string to be parsed.
  39  *      argc_ptr (int *)
  40  *              Where to put the "argc" (number of tokens) value.
  41  *      argv_ptr (char ***)
  42  *              Where to put the series of pointers to parsed tokens.
  43  * Returns:
  44  *      error (0 - success, non-zero on failure)
  45  */
  46
  47 #define NEW_ARGV(old,n) (char **)realloc((char *)old,\
  48                                          (unsigned)(n+2)*sizeof(char*))
  49
  50 int ss_parse (sci_idx, line_ptr, argc_ptr, argv_ptr, quiet)
  51     int sci_idx;
  52     register char *line_ptr;
  53     int *argc_ptr;
  54     char ***argv_ptr;
  55     int quiet;
  56 {
  57     register char **argv, *cp;
  58     register int argc;
  59     register enum parse_mode parse_mode;
  60
  61     argv = (char **) malloc (sizeof(char *));
  62     if (argv == (char **)NULL) {
  63         if (!quiet)
  64             ss_error(sci_idx, errno, "Can't allocate storage");
  65         *argc_ptr = 0;
  66         *argv_ptr = argv;
  67         return(ENOMEM);
  68     }
  69     *argv = (char *)NULL;
  70
  71     argc = 0;
  72
  73     parse_mode = WHITESPACE;    /* flushing whitespace */
  74     cp = line_ptr;              /* cp is for output */
  75     while (1) {
  76 #ifdef DEBUG
  77         {
  78             printf ("character `%c', mode %d\n", *line_ptr, parse_mode);
  79         }
  80 #endif
  81         while (parse_mode == WHITESPACE) {
  82             if (*line_ptr == '\0')
  83                 goto end_of_line;
  84             if (*line_ptr == ' ' || *line_ptr == '\t') {
  85                 line_ptr++;
  86                 continue;
  87             }
  88             if (*line_ptr == '"') {
  89                 /* go to quoted-string mode */
  90                 parse_mode = QUOTED_STRING;
  91                 cp = line_ptr++;
  92                 argv = NEW_ARGV (argv, argc);
  93                 argv[argc++] = cp;
  94                 argv[argc] = NULL;
  95             }
  96             else {
  97                 /* random-token mode */
  98                 parse_mode = TOKEN;
  99                 cp = line_ptr;
 100                 argv = NEW_ARGV (argv, argc);
 101                 argv[argc++] = line_ptr;
 102                 argv[argc] = NULL;
 103             }
 104         }
 105         while (parse_mode == TOKEN) {
 106             if (*line_ptr == '\0') {
 107                 *cp++ = '\0';
 108                 goto end_of_line;
 109             }
 110             else if (*line_ptr == ' ' || *line_ptr == '\t') {
 111                 *cp++ = '\0';
 112                 line_ptr++;
 113                 parse_mode = WHITESPACE;
 114             }
 115             else if (*line_ptr == '"') {
 116                 line_ptr++;
 117                 parse_mode = QUOTED_STRING;
 118             }
 119             else {
 120                 *cp++ = *line_ptr++;
 121             }
 122         }
 123         while (parse_mode == QUOTED_STRING) {
 124             if (*line_ptr == '\0') {
 125                 if (!quiet)
 126                     ss_error (sci_idx, 0,
 127                         "Unbalanced quotes in command line");
 128                 free (argv);
 129                 *argc_ptr = 0;
 130                 *argv_ptr = NULL;
 131                 return (-1);
 132             }
 133             else if (*line_ptr == '"') {
 134                 if (*++line_ptr == '"') {
 135                     *cp++ = '"';
 136                     line_ptr++;
 137                 }
 138                 else {
 139                     parse_mode = TOKEN;
 140                 }
 141             }
 142             else {
 143                 *cp++ = *line_ptr++;
 144             }
 145         }
 146     }
 147 end_of_line:
 148     *argc_ptr = argc;
 149 #ifdef DEBUG
 150     {
 151         int i;
 152         printf ("argc = %d\n", argc);
 153         for (i = 0; i <= argc; i++)
 154             printf ("\targv[%2d] = `%s'\n", i,
 155                     argv[i] ? argv[i] : "<NULL>");
 156     }
 157 #endif
 158     *argv_ptr = argv;
 159     return(0);
 160 }