new

src/cmd/getflags/funcgetflags.c

@@ -0,0 +1,267 @@
+#include <u.h>
+#include <libc.h>
+#include <ctype.h>
+#include "getflags.h"
+
+char **flag[NFLAG];
+char cmdline[NCMDLINE+1];
+char *cmdname;
+char *flagset[];
+char *flagset[]={"<flag>"};
+static char *flagarg="";
+static void reverse(char **, char **);
+static int scanflag(int, char *);
+static int reason;
+#define	RESET	1
+#define	ARGCCOUNT	2
+#define	FLAGSYN	3
+#define	BADFLAG	4
+static int badflag;
+char *getflagsargv[NGETFLAGSARGV+2];	/* original argv stored here for people who need it */
+
+int
+getflags(int argc, char *argv[], char *flags)
+{
+	char *s, *t;
+	int i, j, c, count;
+	flagarg=flags;
+	if(cmdname==0){
+		cmdname=argv[0];
+		for(i=0;i!=argc && i!=NGETFLAGSARGV;i++) getflagsargv[i]=argv[i];
+		if(argc>NGETFLAGSARGV) getflagsargv[i++]="...";
+		getflagsargv[i]=0;
+	}
+	s=cmdline;
+	for(i=0;i!=argc;i++){
+		for(t=argv[i];*t;)
+			if(s!=&cmdline[NCMDLINE])
+				*s++=*t++;
+			else
+				break;
+		if(i!=argc-1 && s!=&cmdline[NCMDLINE])
+			*s++=' ';
+	}
+	*s='\0';
+	i=1;
+	while(i!=argc && argv[i][0]=='-'){
+		s=argv[i]+1;
+		if(*s=='\0'){	/* if argument is "-", stop scanning and delete it */
+			for(j=i+1;j<=argc;j++)
+				argv[j-1]=argv[j];
+			return argc-1;
+		}
+		while(*s){
+			c=*s++;
+			count=scanflag(c, flags);
+			if(count==-1) return -1;
+			if(flag[c]){ reason=RESET; badflag=c; return -1; }
+			if(count==0){
+				flag[c]=flagset;
+				if(*s=='\0'){
+					for(j=i+1;j<=argc;j++)
+						argv[j-1]=argv[j];
+					--argc;
+				}
+			}
+			else{
+				if(*s=='\0'){
+					for(j=i+1;j<=argc;j++)
+						argv[j-1]=argv[j];
+					--argc;
+					s=argv[i];
+				}
+				if(argc-i<count){
+					reason=ARGCCOUNT;
+					badflag=c;
+					return -1;
+				}
+				reverse(argv+i, argv+argc);
+				reverse(argv+i, argv+argc-count);
+				reverse(argv+argc-count+1, argv+argc);
+				argc-=count;
+				flag[c]=argv+argc+1;
+				flag[c][0]=s;
+				s="";
+			}
+		}
+	}
+	return argc;
+}
+
+void
+static reverse(char **p, char **q)
+{
+	register char *t;
+	for(;p<q;p++,--q){ t=*p; *p=*q; *q=t; }
+}
+
+static int
+scanflag(int c, char *f)
+{
+	int fc, count;
+	if(0<=c && c<NFLAG) while(*f){
+		if(*f==' '){
+			f++;
+			continue;
+		}
+		fc=*f++;
+		if(*f==':'){
+			f++;
+			if(!isdigit(*f)){ reason=FLAGSYN; return -1; }
+			count=strtol(f, &f, 10);
+		}
+		else
+			count=0;
+		if(*f=='['){
+			int depth=1;
+			do{
+				f++;
+				if(*f=='\0'){ reason=FLAGSYN; return -1; }
+				if(*f=='[') depth++;
+				if(*f==']') depth--;
+			}while(depth>0);
+			f++;
+		}
+		if(c==fc) return count;
+	}
+	reason=BADFLAG;
+	badflag=c;
+	return -1;
+}
+
+static void errn(char *, int), errs(char *), errc(int);
+
+void
+usage(char *tail)
+{
+	char *s, *t, c;
+	int count, nflag=0;
+	switch(reason){
+	case RESET:
+		errs("Flag -");
+		errc(badflag);
+		errs(": set twice\n");
+		break;
+	case ARGCCOUNT:
+		errs("Flag -");
+		errc(badflag);
+		errs(": too few arguments\n");
+		break;
+	case FLAGSYN:
+		errs("Bad argument to getflags!\n");
+		break;
+	case BADFLAG:
+		errs("Illegal flag -");
+		errc(badflag);
+		errc('\n');
+		break;
+	}
+	errs("Usage: ");
+	errs(cmdname);
+	for(s=flagarg;*s;){
+		c=*s;
+		if(*s++==' ') continue;
+		if(*s==':'){
+			s++;
+			count=strtol(s, &s, 10);
+		}
+		else count=0;
+		if(count==0){
+			if(nflag==0) errs(" [-");
+			nflag++;
+			errc(c);
+		}
+		if(*s=='['){
+			int depth=1;
+			s++;
+			for(;*s!='\0' && depth>0; s++)
+				if (*s==']') depth--;
+				else if (*s=='[') depth++;
+		}
+	}
+	if(nflag) errs("]");
+	for(s=flagarg;*s;){
+		c=*s;
+		if(*s++==' ') continue;
+		if(*s==':'){
+			s++;
+			count=strtol(s, &s, 10);
+		}
+		else count=0;
+		if(count!=0){
+			errs(" [-");
+			errc(c);
+			if(*s=='['){
+				int depth=1;
+				s++;
+				t=s;
+				for(;*s!='\0' && depth>0; s++)
+					if (*s==']') depth--;
+					else if (*s=='[') depth++;
+				errs(" ");
+				errn(t, s-t);
+			}
+			else
+				while(count--) errs(" arg");
+			errs("]");
+		}
+		else if(*s=='['){
+			int depth=1;
+			s++;
+			for(;*s!='\0' && depth>0; s++)
+				if (*s==']') depth--;
+				else if (*s=='[') depth++;
+		}
+	}
+	if(tail){
+		errs(" ");
+		errs(tail);
+	}
+	errs("\n");
+	exits("usage");
+}
+
+static void
+errn(char *s, int count)
+{
+	while(count){ errc(*s++); --count; }
+}
+
+static void
+errs(char *s)
+{
+	while(*s) errc(*s++);
+}
+
+#define	NBUF	80
+static char buf[NBUF], *bufp=buf;
+
+static void
+errc(int c){
+	*bufp++=c;
+	if(bufp==&buf[NBUF] || c=='\n'){
+		write(2, buf, bufp-buf);
+		bufp=buf;
+	}
+}
+
+#ifdef TEST
+#include <stdio.h>
+main(int argc, char *argv[])
+{
+	int c, i, n;
+	if(argc<3){
+		fprint(2, "Usage: %s flags cmd ...\n", argv[0]);
+		exits("usage");
+	}
+	n=getflags(argc-2, argv+2, argv[1]);
+	if(n<0) usage("...");
+	putchar('\n');
+	for(c=0;c!=128;c++) if(flag[c]){
+		print("\t-.%c. ", c);
+		n=scanflag(c, argv[1]);
+		for(i=0;i!=n;i++) print(" <%s>", flag[c][i]);
+		putchar('\n');
+	}
+}
+#endif