various tweaks.
diff --git a/src/libcomplete/complete.c b/src/libcomplete/complete.c
new file mode 100644
index 0000000..3a06447
--- /dev/null
+++ b/src/libcomplete/complete.c
@@ -0,0 +1,139 @@
+#include <u.h>
+#include <libc.h>
+#include "complete.h"
+
+static int
+longestprefixlength(char *a, char *b, int n)
+{
+ int i, w;
+ Rune ra, rb;
+
+ for(i=0; i<n; i+=w){
+ w = chartorune(&ra, a);
+ chartorune(&rb, b);
+ if(ra != rb)
+ break;
+ a += w;
+ b += w;
+ }
+ return i;
+}
+
+void
+freecompletion(Completion *c)
+{
+ if(c){
+ free(c->filename);
+ free(c);
+ }
+}
+
+static int
+strpcmp(const void *va, const void *vb)
+{
+ char *a, *b;
+
+ a = *(char**)va;
+ b = *(char**)vb;
+ return strcmp(a, b);
+}
+
+Completion*
+complete(char *dir, char *s)
+{
+ long i, l, n, nmatch, len, nbytes;
+ int fd, minlen;
+ Dir *dirp;
+ char **name, *p;
+ ulong* mode;
+ Completion *c;
+
+ if(strchr(s, '/') != nil){
+ werrstr("slash character in name argument to complete()");
+ return nil;
+ }
+
+ fd = open(dir, OREAD);
+ if(fd < 0)
+ return nil;
+
+ n = dirreadall(fd, &dirp);
+ if(n <= 0)
+ return nil;
+
+ /* find longest string, for allocation */
+ len = 0;
+ for(i=0; i<n; i++){
+ l = strlen(dirp[i].name) + 1 + 1; /* +1 for / +1 for \0 */
+ if(l > len)
+ len = l;
+ }
+
+ name = malloc(n*sizeof(char*));
+ mode = malloc(n*sizeof(ulong));
+ c = malloc(sizeof(Completion) + len);
+ if(name == nil || mode == nil || c == nil)
+ goto Return;
+ memset(c, 0, sizeof(Completion));
+
+ /* find the matches */
+ len = strlen(s);
+ nmatch = 0;
+ minlen = 1000000;
+ for(i=0; i<n; i++)
+ if(strncmp(s, dirp[i].name, len) == 0){
+ name[nmatch] = dirp[i].name;
+ mode[nmatch] = dirp[i].mode;
+ if(minlen > strlen(dirp[i].name))
+ minlen = strlen(dirp[i].name);
+ nmatch++;
+ }
+
+ if(nmatch > 0) {
+ /* report interesting results */
+ /* trim length back to longest common initial string */
+ for(i=1; i<nmatch; i++)
+ minlen = longestprefixlength(name[0], name[i], minlen);
+
+ /* build the answer */
+ c->complete = (nmatch == 1);
+ c->advance = c->complete || (minlen > len);
+ c->string = (char*)(c+1);
+ memmove(c->string, name[0]+len, minlen-len);
+ if(c->complete)
+ c->string[minlen++ - len] = (mode[0]&DMDIR)? '/' : ' ';
+ c->string[minlen - len] = '\0';
+ } else {
+ /* no match, so return all possible strings */
+ for(i=0; i<n; i++){
+ name[i] = dirp[i].name;
+ mode[i] = dirp[i].mode;
+ }
+ nmatch = n;
+ }
+
+ /* attach list of names */
+ nbytes = nmatch * sizeof(char*);
+ for(i=0; i<nmatch; i++)
+ nbytes += strlen(name[i]) + 1 + 1;
+ c->filename = malloc(nbytes);
+ if(c->filename == nil)
+ goto Return;
+ p = (char*)(c->filename + nmatch);
+ for(i=0; i<nmatch; i++){
+ c->filename[i] = p;
+ strcpy(p, name[i]);
+ p += strlen(p);
+ if(mode[i] & DMDIR)
+ *p++ = '/';
+ *p++ = '\0';
+ }
+ c->nfile = nmatch;
+ qsort(c->filename, c->nfile, sizeof(c->filename[0]), strpcmp);
+
+ Return:
+ free(name);
+ free(mode);
+ free(dirp);
+ return c;
+}
