1 #include <u.h>
2 #include <libc.h>
3 #include <ctype.h>
4 #include "getflags.h"
5 
6 char **flag[NFLAG];
7 char cmdline[NCMDLINE+1];
8 char *cmdname;
9 char *flagset[];
10 char *flagset[]={"<flag>"};
11 static char *flagarg="";
12 static void reverse(char **, char **);
13 static int scanflag(int, char *);
14 static int reason;
15 #define	RESET	1
16 #define	ARGCCOUNT	2
17 #define	FLAGSYN	3
18 #define	BADFLAG	4
19 static int badflag;
20 char *getflagsargv[NGETFLAGSARGV+2];	/* original argv stored here for people who need it */
21 
22 int
23 getflags(int argc, char *argv[], char *flags)
24 {
25 	char *s, *t;
26 	int i, j, c, count;
27 	flagarg=flags;
28 	if(cmdname==0){
29 		cmdname=argv[0];
30 		for(i=0;i!=argc && i!=NGETFLAGSARGV;i++) getflagsargv[i]=argv[i];
31 		if(argc>NGETFLAGSARGV) getflagsargv[i++]="...";
32 		getflagsargv[i]=0;
33 	}
34 	s=cmdline;
35 	for(i=0;i!=argc;i++){
36 		for(t=argv[i];*t;)
37 			if(s!=&cmdline[NCMDLINE])
38 				*s++=*t++;
39 			else
40 				break;
41 		if(i!=argc-1 && s!=&cmdline[NCMDLINE])
42 			*s++=' ';
43 	}
44 	*s='\0';
45 	i=1;
46 	while(i!=argc && argv[i][0]=='-'){
47 		s=argv[i]+1;
48 		if(*s=='\0'){	/* if argument is "-", stop scanning and delete it */
49 			for(j=i+1;j<=argc;j++)
50 				argv[j-1]=argv[j];
51 			return argc-1;
52 		}
53 		while(*s){
54 			c=*s++;
55 			count=scanflag(c, flags);
56 			if(count==-1) return -1;
57 			if(flag[c]){ reason=RESET; badflag=c; return -1; }
58 			if(count==0){
59 				flag[c]=flagset;
60 				if(*s=='\0'){
61 					for(j=i+1;j<=argc;j++)
62 						argv[j-1]=argv[j];
63 					--argc;
64 				}
65 			}
66 			else{
67 				if(*s=='\0'){
68 					for(j=i+1;j<=argc;j++)
69 						argv[j-1]=argv[j];
70 					--argc;
71 					s=argv[i];
72 				}
73 				if(argc-i<count){
74 					reason=ARGCCOUNT;
75 					badflag=c;
76 					return -1;
77 				}
78 				reverse(argv+i, argv+argc);
79 				reverse(argv+i, argv+argc-count);
80 				reverse(argv+argc-count+1, argv+argc);
81 				argc-=count;
82 				flag[c]=argv+argc+1;
83 				flag[c][0]=s;
84 				s="";
85 			}
86 		}
87 	}
88 	return argc;
89 }
90 
91 void
92 static reverse(char **p, char **q)
93 {
94 	register char *t;
95 	for(;p<q;p++,--q){ t=*p; *p=*q; *q=t; }
96 }
97 
98 static int
99 scanflag(int c, char *f)
100 {
101 	int fc, count;
102 	if(0<=c && c<NFLAG) while(*f){
103 		if(*f==' '){
104 			f++;
105 			continue;
106 		}
107 		fc=*f++;
108 		if(*f==':'){
109 			f++;
110 			if(!isdigit((uchar)*f)){ reason=FLAGSYN; return -1; }
111 			count=strtol(f, &f, 10);
112 		}
113 		else
114 			count=0;
115 		if(*f=='['){
116 			int depth=1;
117 			do{
118 				f++;
119 				if(*f=='\0'){ reason=FLAGSYN; return -1; }
120 				if(*f=='[') depth++;
121 				if(*f==']') depth--;
122 			}while(depth>0);
123 			f++;
124 		}
125 		if(c==fc) return count;
126 	}
127 	reason=BADFLAG;
128 	badflag=c;
129 	return -1;
130 }
131 
132 static void errn(char *, int), errs(char *), errc(int);
133 
134 void
135 usage(char *tail)
136 {
137 	char *s, *t, c;
138 	int count, nflag=0;
139 	switch(reason){
140 	case RESET:
141 		errs("Flag -");
142 		errc(badflag);
143 		errs(": set twice\n");
144 		break;
145 	case ARGCCOUNT:
146 		errs("Flag -");
147 		errc(badflag);
148 		errs(": too few arguments\n");
149 		break;
150 	case FLAGSYN:
151 		errs("Bad argument to getflags!\n");
152 		break;
153 	case BADFLAG:
154 		errs("Illegal flag -");
155 		errc(badflag);
156 		errc('\n');
157 		break;
158 	}
159 	errs("Usage: ");
160 	errs(cmdname);
161 	for(s=flagarg;*s;){
162 		c=*s;
163 		if(*s++==' ') continue;
164 		if(*s==':'){
165 			s++;
166 			count=strtol(s, &s, 10);
167 		}
168 		else count=0;
169 		if(count==0){
170 			if(nflag==0) errs(" [-");
171 			nflag++;
172 			errc(c);
173 		}
174 		if(*s=='['){
175 			int depth=1;
176 			s++;
177 			for(;*s!='\0' && depth>0; s++)
178 				if (*s==']') depth--;
179 				else if (*s=='[') depth++;
180 		}
181 	}
182 	if(nflag) errs("]");
183 	for(s=flagarg;*s;){
184 		c=*s;
185 		if(*s++==' ') continue;
186 		if(*s==':'){
187 			s++;
188 			count=strtol(s, &s, 10);
189 		}
190 		else count=0;
191 		if(count!=0){
192 			errs(" [-");
193 			errc(c);
194 			if(*s=='['){
195 				int depth=1;
196 				s++;
197 				t=s;
198 				for(;*s!='\0' && depth>0; s++)
199 					if (*s==']') depth--;
200 					else if (*s=='[') depth++;
201 				errs(" ");
202 				errn(t, s-t);
203 			}
204 			else
205 				while(count--) errs(" arg");
206 			errs("]");
207 		}
208 		else if(*s=='['){
209 			int depth=1;
210 			s++;
211 			for(;*s!='\0' && depth>0; s++)
212 				if (*s==']') depth--;
213 				else if (*s=='[') depth++;
214 		}
215 	}
216 	if(tail){
217 		errs(" ");
218 		errs(tail);
219 	}
220 	errs("\n");
221 	exits("usage");
222 }
223 
224 static void
225 errn(char *s, int count)
226 {
227 	while(count){ errc(*s++); --count; }
228 }
229 
230 static void
231 errs(char *s)
232 {
233 	while(*s) errc(*s++);
234 }
235 
236 #define	NBUF	80
237 static char buf[NBUF], *bufp=buf;
238 
239 static void
240 errc(int c){
241 	*bufp++=c;
242 	if(bufp==&buf[NBUF] || c=='\n'){
243 		write(2, buf, bufp-buf);
244 		bufp=buf;
245 	}
246 }
247 
248 #ifdef TEST
249 #include <stdio.h>
250 main(int argc, char *argv[])
251 {
252 	int c, i, n;
253 	if(argc<3){
254 		fprint(2, "Usage: %s flags cmd ...\n", argv[0]);
255 		exits("usage");
256 	}
257 	n=getflags(argc-2, argv+2, argv[1]);
258 	if(n<0) usage("...");
259 	putchar('\n');
260 	for(c=0;c!=128;c++) if(flag[c]){
261 		print("\t-.%c. ", c);
262 		n=scanflag(c, argv[1]);
263 		for(i=0;i!=n;i++) print(" <%s>", flag[c][i]);
264 		putchar('\n');
265 	}
266 }
267 #endif