summaryrefslogtreecommitdiff
path: root/src/pcheck.cc
blob: d5401f7d9715628ac443b129a87635b6de47adf6 (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
150
151
152
153
154
/*
 *  Copyright 2006-2012 Adrian Thurston <thurston@complang.org>
 */

/*  This file is part of Colm.
 *
 *  Colm 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 2 of the License, or
 *  (at your option) any later version.
 * 
 *  Colm 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 Colm; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 */

#include "pcheck.h"
#include <assert.h>

/* Construct a new parameter checker with for paramSpec. */
ParamCheck::ParamCheck( const char *paramSpec, int argc,  const char **argv )
:
	state(noparam),
	argOffset(0),
	curArg(0),
	iCurArg(1),
	paramSpec(paramSpec), 
	argc(argc), 
	argv(argv)
{
}

/* Check a single option. Returns the index of the next parameter.  Sets p to
 * the arg character if valid, 0 otherwise.  Sets parg to the parameter arg if
 * there is one, NULL otherwise. */
bool ParamCheck::check()
{
	bool requiresParam;

	if ( iCurArg >= argc ) {            /* Off the end of the arg list. */
		state = noparam;
		return false;
	}

	if ( argOffset != 0 && *argOffset == 0 ) {
		/* We are at the end of an arg string. */
		iCurArg += 1;
		if ( iCurArg >= argc ) {
			state = noparam;
			return false;
		}
		argOffset = 0;
	}

	if ( argOffset == 0 ) {
		/* Set the current arg. */
		curArg = argv[iCurArg];

		/* We are at the beginning of an arg string. */
		if ( argv[iCurArg] == 0 ||        /* Argv[iCurArg] is null. */
			 argv[iCurArg][0] != '-' ||   /* Not a param. */
			 argv[iCurArg][1] == 0 ) {    /* Only a dash. */
			parameter = 0;
			parameterArg = 0;

			iCurArg += 1;
			state = noparam;
			return true;
		}
		argOffset = argv[iCurArg] + 1;
	}

	/* Get the arg char. */
	char argChar = *argOffset;
	
	/* Loop over all the parms and look for a match. */
	const char *pSpec = paramSpec;
	while ( *pSpec != 0 ) {
		char pSpecChar = *pSpec;

		/* If there is a ':' following the char then
		 * it requires a parm.  If a parm is required
		 * then move ahead two in the parmspec. Otherwise
		 * move ahead one in the parm spec. */
		if ( pSpec[1] == ':' ) {
			requiresParam = true;
			pSpec += 2;
		}
		else {
			requiresParam = false;
			pSpec += 1;
		}

		/* Do we have a match. */
		if ( argChar == pSpecChar ) {
			if ( requiresParam ) {
				if ( argOffset[1] == 0 ) {
					/* The param must follow. */
					if ( iCurArg + 1 == argc ) {
						/* We are the last arg so there
						 * cannot be a parameter to it. */
						parameter = argChar;
						parameterArg = 0;
						iCurArg += 1;
						argOffset = 0;
						state = invalid;
						return true;
					}
					else {
						/* the parameter to the arg is the next arg. */
						parameter = pSpecChar;
						parameterArg = argv[iCurArg + 1];
						iCurArg += 2;
						argOffset = 0;
						state = match;
						return true;
					}
				}
				else {
					/* The param for the arg is built in. */
					parameter = pSpecChar;
					parameterArg = argOffset + 1;
					iCurArg += 1;
					argOffset = 0;
					state = match;
					return true;
				}
			}
			else {
				/* Good, we matched the parm and no
				 * arg is required. */
				parameter = pSpecChar;
				parameterArg = 0;
				argOffset += 1;
				state = match;
				return true;
			}
		}
	}

	/* We did not find a match. Bad Argument. */
	parameter = argChar;
	parameterArg = 0;
	argOffset += 1;
	state = invalid;
	return true;
}