summaryrefslogtreecommitdiff
path: root/lib/ss/parse.c
blob: b70ad1654ddfd3830d3b2c521592a5ab46f7973a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
/*
 * Copyright 1987, 1988 by MIT Student Information Processing Board
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose is hereby granted, provided that
 * the names of M.I.T. and the M.I.T. S.I.P.B. not be used in
 * advertising or publicity pertaining to distribution of the software
 * without specific, written prior permission.  M.I.T. and the
 * M.I.T. S.I.P.B. make no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without
 * express or implied warranty.
 */

#include "config.h"
#ifdef HAS_STDLIB_H
#include <stdlib.h>
#endif
#include <string.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif

#include "ss_internal.h"

enum parse_mode { WHITESPACE, TOKEN, QUOTED_STRING };

/*
 * parse(line_ptr, argc_ptr)
 *
 * Function:
 *      Parses line, dividing at whitespace, into tokens, returns
 *      the "argc" and "argv" values.
 * Arguments:
 *      line_ptr (char *)
 *              Pointer to text string to be parsed.
 *      argc_ptr (int *)
 *              Where to put the "argc" (number of tokens) value.
 * Returns:
 *      argv (char **)
 *              Series of pointers to parsed tokens.
 */

#define NEW_ARGV(old,n) (char **)realloc((char *)old,\
					 (unsigned)(n+2)*sizeof(char*))

char **ss_parse (sci_idx, line_ptr, argc_ptr)
    int sci_idx;
    register char *line_ptr;
    int *argc_ptr;
{
    register char **argv, *cp;
    register int argc;
    register enum parse_mode parse_mode;

    argv = (char **) malloc (sizeof(char *));
    if (argv == (char **)NULL) {
	ss_error(sci_idx, errno, "Can't allocate storage");
	*argc_ptr = 0;
	return(argv);
    }
    *argv = (char *)NULL;

    argc = 0;

    parse_mode = WHITESPACE;	/* flushing whitespace */
    cp = line_ptr;		/* cp is for output */
    while (1) {
#ifdef DEBUG
	{
	    printf ("character `%c', mode %d\n", *line_ptr, parse_mode);
	}
#endif
	while (parse_mode == WHITESPACE) {
	    if (*line_ptr == '\0')
		goto end_of_line;
	    if (*line_ptr == ' ' || *line_ptr == '\t') {
		line_ptr++;
		continue;
	    }
	    if (*line_ptr == '"') {
		/* go to quoted-string mode */
		parse_mode = QUOTED_STRING;
		cp = line_ptr++;
		argv = NEW_ARGV (argv, argc);
		argv[argc++] = cp;
		argv[argc] = NULL;
	    }
	    else {
		/* random-token mode */
		parse_mode = TOKEN;
		cp = line_ptr;
		argv = NEW_ARGV (argv, argc);
		argv[argc++] = line_ptr;
		argv[argc] = NULL;
	    }
	}
	while (parse_mode == TOKEN) {
	    if (*line_ptr == '\0') {
		*cp++ = '\0';
		goto end_of_line;
	    }
	    else if (*line_ptr == ' ' || *line_ptr == '\t') {
		*cp++ = '\0';
		line_ptr++;
		parse_mode = WHITESPACE;
	    }
	    else if (*line_ptr == '"') {
		line_ptr++;
		parse_mode = QUOTED_STRING;
	    }
	    else {
		*cp++ = *line_ptr++;
	    }
	}
	while (parse_mode == QUOTED_STRING) {
	    if (*line_ptr == '\0') {
		ss_error (sci_idx, 0,
			  "Unbalanced quotes in command line");
		free (argv);
		*argc_ptr = 0;
		return NULL;
	    }
	    else if (*line_ptr == '"') {
		if (*++line_ptr == '"') {
		    *cp++ = '"';
		    line_ptr++;
		}
		else {
		    parse_mode = TOKEN;
		}
	    }
	    else {
		*cp++ = *line_ptr++;
	    }
	}
    }
end_of_line:
    *argc_ptr = argc;
#ifdef DEBUG
    {
	int i;
	printf ("argc = %d\n", argc);
	for (i = 0; i <= argc; i++)
	    printf ("\targv[%2d] = `%s'\n", i,
		    argv[i] ? argv[i] : "<NULL>");
    }
#endif
    return(argv);
}