1 files changed, 70 insertions, 0 deletions
diff --git a/sys/src/cmd/mothra/urlcanon.c b/sys/src/cmd/mothra/urlcanon.c
new file mode 100644
index 000000000..2ffaeb750
--- /dev/null
+++ b/sys/src/cmd/mothra/urlcanon.c
@@ -0,0 +1,70 @@
+#include <u.h>
+#include <libc.h>
+void *emalloc(int n){
+	void *p;
+	p=malloc(n);
+	if(p==0){
+		fprint(2, "can't malloc\n");
+		exits("no mem");
+	}
+	return p;
+}
+void urlcanon(char *name){
+	char *s, *t;
+	char **comp, **p, **q;
+	int rooted;
+	rooted=name[0]=='/';
+	/*
+	 * Break the name into a list of components
+	 */
+	comp=emalloc(strlen(name)*sizeof(char *));
+	p=comp;
+	*p++=name;
+	for(s=name;;s++){
+		if(*s=='/'){
+			*p++=s+1;
+			*s='\0';
+		}
+		else if(*s=='\0')
+			break;
+	}
+	*p=0;
+	/*
+	 * go through the component list, deleting components that are empty (except
+	 * the last component) or ., and any .. and its non-.. predecessor.
+	 */
+	p=q=comp;
+	while(*p){
+		if(strcmp(*p, "")==0 && p[1]!=0
+		|| strcmp(*p, ".")==0)
+			p++;
+		else if(strcmp(*p, "..")==0 && q!=comp && strcmp(q[-1], "..")!=0){
+			--q;
+			p++;
+		}
+		else
+			*q++=*p++;
+	}
+	*q=0;
+	/*
+	 * rebuild the path name
+	 */
+	s=name;
+	if(rooted) *s++='/';
+	for(p=comp;*p;p++){
+		t=*p;
+		while(*t) *s++=*t++;
+		if(p[1]!=0) *s++='/';
+	}
+	*s='\0';
+	free(comp);
+}
+void main(int argc, char *argv[]){
+	int i;
+	for(i=1;i!=argc;i++){
+		print("%s: ", argv[i]);
+		urlcanon(argv[i]);
+		print("%s\n", argv[i]);
+	}
+	exits(0);
+}