mmc.c revision 45541d55fa50e385894d22960f2526b6c7f68d52 
1/*
2 * This program is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU General Public
4 * License v2 as published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
9 * General Public License for more details.
10 *
11 * You should have received a copy of the GNU General Public
12 * License along with this program; if not, write to the
13 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
14 * Boston, MA 021110-1307, USA.
15 *
16 * (This code is based on btrfs-progs/btrfs.c.)
17 */
18
19#define _GNU_SOURCE
20#include <stdio.h>
21#include <stdlib.h>
22#include <string.h>
23
24#include "mmc_cmds.h"
25
26#define MMC_VERSION	"0.1"
27
28#define BASIC_HELP 0
29#define ADVANCED_HELP 1
30
31typedef int (*CommandFunction)(int argc, char **argv);
32
33struct Command {
34	CommandFunction	func;	/* function which implements the command */
35	int	nargs;		/* if == 999, any number of arguments
36				   if >= 0, number of arguments,
37				   if < 0, _minimum_ number of arguments */
38	char	*verb;		/* verb */
39	char	*help;		/* help lines; from the 2nd line onward they
40                                   are automatically indented */
41        char    *adv_help;      /* advanced help message; from the 2nd line
42                                   onward they are automatically indented */
43
44	/* the following fields are run-time filled by the program */
45	char	**cmds;		/* array of subcommands */
46	int	ncmds;		/* number of subcommand */
47};
48
49static struct Command commands[] = {
50	/*
51	 *	avoid short commands different for the case only
52	 */
53	{ do_read_extcsd, -1,
54	  "extcsd read", "<device>\n"
55		"Print extcsd data from <device>.",
56	  NULL
57	},
58	{ do_write_extcsd, -1,
59	  "extcsd write", "<device>\n"
60		"Write extcsd data to <device>.",
61	  NULL
62	},
63	{ 0, 0, 0, 0 }
64};
65
66static char *get_prgname(char *programname)
67{
68	char	*np;
69	np = strrchr(programname,'/');
70	if(!np)
71		np = programname;
72	else
73		np++;
74
75	return np;
76}
77
78static void print_help(char *programname, struct Command *cmd, int helptype)
79{
80	char	*pc;
81
82	printf("\t%s %s ", programname, cmd->verb );
83
84	if (helptype == ADVANCED_HELP && cmd->adv_help)
85		for(pc = cmd->adv_help; *pc; pc++){
86			putchar(*pc);
87			if(*pc == '\n')
88				printf("\t\t");
89		}
90	else
91		for(pc = cmd->help; *pc; pc++){
92			putchar(*pc);
93			if(*pc == '\n')
94				printf("\t\t");
95		}
96
97	putchar('\n');
98}
99
100static void help(char *np)
101{
102	struct Command *cp;
103
104	printf("Usage:\n");
105	for( cp = commands; cp->verb; cp++ )
106		print_help(np, cp, BASIC_HELP);
107
108	printf("\n\t%s help|--help|-h\n\t\tShow the help.\n",np);
109	printf("\n\t%s <cmd> --help\n\t\tShow detailed help for a command or subset of commands.\n",np);
110	printf("\n%s\n", MMC_VERSION);
111}
112
113static int split_command(char *cmd, char ***commands)
114{
115	int	c, l;
116	char	*p, *s;
117
118	for( *commands = 0, l = c = 0, p = s = cmd ; ; p++, l++ ){
119		if ( *p && *p != ' ' )
120			continue;
121
122		/* c + 2 so that we have room for the null */
123		(*commands) = realloc( (*commands), sizeof(char *)*(c + 2));
124		(*commands)[c] = strndup(s, l);
125		c++;
126		l = 0;
127		s = p+1;
128		if( !*p ) break;
129	}
130
131	(*commands)[c] = 0;
132	return c;
133}
134
135/*
136	This function checks if the passed command is ambiguous
137*/
138static int check_ambiguity(struct Command *cmd, char **argv){
139	int		i;
140	struct Command	*cp;
141	/* check for ambiguity */
142	for( i = 0 ; i < cmd->ncmds ; i++ ){
143		int match;
144		for( match = 0, cp = commands; cp->verb; cp++ ){
145			int	j, skip;
146			char	*s1, *s2;
147
148			if( cp->ncmds < i )
149				continue;
150
151			for( skip = 0, j = 0 ; j < i ; j++ )
152				if( strcmp(cmd->cmds[j], cp->cmds[j])){
153					skip=1;
154					break;
155				}
156			if(skip)
157				continue;
158
159			if( !strcmp(cmd->cmds[i], cp->cmds[i]))
160				continue;
161			for(s2 = cp->cmds[i], s1 = argv[i+1];
162				*s1 == *s2 && *s1; s1++, s2++ ) ;
163			if( !*s1 )
164				match++;
165		}
166		if(match){
167			int j;
168			fprintf(stderr, "ERROR: in command '");
169			for( j = 0 ; j <= i ; j++ )
170				fprintf(stderr, "%s%s",j?" ":"", argv[j+1]);
171			fprintf(stderr, "', '%s' is ambiguous\n",argv[j]);
172			return -2;
173		}
174	}
175	return 0;
176}
177
178/*
179 * This function, compacts the program name and the command in the first
180 * element of the '*av' array
181 */
182static int prepare_args(int *ac, char ***av, char *prgname, struct Command *cmd ){
183
184	char	**ret;
185	int	i;
186	char	*newname;
187
188	ret = (char **)malloc(sizeof(char*)*(*ac+1));
189	newname = (char*)malloc(strlen(prgname)+strlen(cmd->verb)+2);
190	if( !ret || !newname ){
191		free(ret);
192		free(newname);
193		return -1;
194	}
195
196	ret[0] = newname;
197	for(i=0; i < *ac ; i++ )
198		ret[i+1] = (*av)[i];
199
200	strcpy(newname, prgname);
201	strcat(newname, " ");
202	strcat(newname, cmd->verb);
203
204	(*ac)++;
205	*av = ret;
206
207	return 0;
208
209}
210
211/*
212	This function performs the following jobs:
213	- show the help if '--help' or 'help' or '-h' are passed
214	- verify that a command is not ambiguous, otherwise show which
215	  part of the command is ambiguous
216	- if after a (even partial) command there is '--help' show detailed help
217	  for all the matching commands
218	- if the command doesn't match show an error
219	- finally, if a command matches, they return which command matched and
220	  the arguments
221
222	The function return 0 in case of help is requested; <0 in case
223	of uncorrect command; >0 in case of matching commands
224	argc, argv are the arg-counter and arg-vector (input)
225	*nargs_ is the number of the arguments after the command (output)
226	**cmd_  is the invoked command (output)
227	***args_ are the arguments after the command
228
229*/
230static int parse_args(int argc, char **argv,
231		      CommandFunction *func_,
232		      int *nargs_, char **cmd_, char ***args_ )
233{
234	struct Command	*cp;
235	struct Command	*matchcmd=0;
236	char		*prgname = get_prgname(argv[0]);
237	int		i=0, helprequested=0;
238
239	if( argc < 2 || !strcmp(argv[1], "help") ||
240		!strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")){
241		help(prgname);
242		return 0;
243	}
244
245	for( cp = commands; cp->verb; cp++ )
246		if( !cp->ncmds)
247			cp->ncmds = split_command(cp->verb, &(cp->cmds));
248
249	for( cp = commands; cp->verb; cp++ ){
250		int     match;
251
252		if( argc-1 < cp->ncmds )
253			continue;
254		for( match = 1, i = 0 ; i < cp->ncmds ; i++ ){
255			char	*s1, *s2;
256			s1 = cp->cmds[i];
257			s2 = argv[i+1];
258
259			for(s2 = cp->cmds[i], s1 = argv[i+1];
260				*s1 == *s2 && *s1;
261				s1++, s2++ ) ;
262			if( *s1 ){
263				match=0;
264				break;
265			}
266		}
267
268		/* If you understand why this code works ...
269			you are a genious !! */
270		if(argc>i+1 && !strcmp(argv[i+1],"--help")){
271			if(!helprequested)
272				printf("Usage:\n");
273			print_help(prgname, cp, ADVANCED_HELP);
274			helprequested=1;
275			continue;
276		}
277
278		if(!match)
279			continue;
280
281		matchcmd = cp;
282		*nargs_  = argc-matchcmd->ncmds-1;
283		*cmd_ = matchcmd->verb;
284		*args_ = argv+matchcmd->ncmds+1;
285		*func_ = cp->func;
286
287		break;
288	}
289
290	if(helprequested){
291		printf("\n%s\n", MMC_VERSION);
292		return 0;
293	}
294
295	if(!matchcmd){
296		fprintf( stderr, "ERROR: unknown command '%s'\n",argv[1]);
297		help(prgname);
298		return -1;
299	}
300
301	if(check_ambiguity(matchcmd, argv))
302		return -2;
303
304	/* check the number of argument */
305	if (matchcmd->nargs < 0 && matchcmd->nargs < -*nargs_ ){
306		fprintf(stderr, "ERROR: '%s' requires minimum %d arg(s)\n",
307			matchcmd->verb, -matchcmd->nargs);
308			return -2;
309	}
310	if(matchcmd->nargs >= 0 && matchcmd->nargs != *nargs_ && matchcmd->nargs != 999){
311		fprintf(stderr, "ERROR: '%s' requires %d arg(s)\n",
312			matchcmd->verb, matchcmd->nargs);
313			return -2;
314	}
315
316        if (prepare_args( nargs_, args_, prgname, matchcmd )){
317                fprintf(stderr, "ERROR: not enough memory\\n");
318		return -20;
319        }
320
321
322	return 1;
323}
324int main(int ac, char **av )
325{
326	char		*cmd=0, **args=0;
327	int		nargs=0, r;
328	CommandFunction func=0;
329
330	r = parse_args(ac, av, &func, &nargs, &cmd, &args);
331	if( r <= 0 ){
332		/* error or no command to parse*/
333		exit(-r);
334	}
335
336	exit(func(nargs, args));
337}
338
339