add directory-examining recursive compare derp(1)

1 files changed, 474 insertions, 0 deletions

diff --git a/sys/src/cmd/derp.c b/sys/src/cmd/derp.c
new file mode 100644
index 000000000..a16ef3b1e
--- /dev/null
+++ b/sys/src/cmd/derp.c
@@ -0,0 +1,474 @@
+#include <u.h>
+#include <libc.h>
+
+int	permcheck = 0;
+int	usercheck = 0;
+int	dumpcheck = 1;
+int	sizecheck = 1;
+int	timecheck = 0;
+
+int	quiet = 0;
+int	errors = 0;
+int	noerror = 0;
+
+void
+error(char *fmt, ...)
+{
+	char buf[ERRMAX];
+	va_list a;
+
+	errors++;
+	if(!quiet){
+		va_start(a, fmt);
+		vsnprint(buf, sizeof(buf), fmt, a);
+		va_end(a);
+
+		fprint(2, "%s: %s\n", argv0, buf);
+	}
+	if(!noerror)
+		exits("errors");
+}
+
+#pragma	varargck	argpos	error	1
+
+enum {
+	BUFSIZE = 8*1024,
+};
+
+int
+cmpfile(char *a, char *b)
+{
+	static uchar buf1[BUFSIZE], buf2[BUFSIZE];
+	int r, n, m, fd1, fd2;
+	
+	if((fd1 = open(a, OREAD)) < 0)
+		error("can't open %s: %r", a);
+	if((fd2 = open(b, OREAD)) < 0)
+		error("can't open %s: %r", b);
+
+	r = fd1 != fd2;
+	if(fd1 >= 0 && fd2 >= 0)
+		do{
+			if((n = readn(fd1, buf1, sizeof(buf1))) < 0){
+				error("can't read %s: %r", a);
+				break;
+			}
+			m = n;
+			if(m == 0)
+				m++;	/* read past eof to verify size */
+			if((m = readn(fd2, buf2, m)) < 0){
+				error("can't read %s: %r", b);
+				break;
+			}
+			if(m != n)
+				break;
+			if(n == 0){
+				r = 0;
+				break;
+			}
+		} while(memcmp(buf1, buf2, n) == 0);
+
+	if(fd1 >= 0)
+		close(fd1);
+	if(fd2 >= 0)
+		close(fd2);
+
+	return r;
+}
+
+int
+samefile(Dir *a, Dir *b)
+{
+	if(a == b)
+		return 1;
+
+	if(a->type == b->type && a->dev == b->dev &&
+		a->qid.type == b->qid.type &&
+		a->qid.path == b->qid.path &&
+		a->qid.vers == b->qid.vers){
+
+		if((a->qid.type & QTDIR) == 0)
+			return 1;
+
+		/*
+		 * directories in /n/dump have the same qid, but
+		 * atime can be used to skip potentially
+		 * untouched subtrees.
+		 */
+		if(dumpcheck && a->atime == b->atime)
+			return 1;
+	}
+
+	return 0;
+}
+
+int
+dcmp(Dir *a, Dir *b)
+{
+	if(a == nil || b == nil)
+		return a != b;
+
+	if(samefile(a, b))
+		return 0;
+
+	if((a->qid.type | b->qid.type) & QTDIR)
+		return 1;
+
+	if((a->mode ^ b->mode) & permcheck)
+		return 1;
+
+	if(usercheck){
+		if(strcmp(a->uid, b->uid) != 0)
+			return 1;
+		if(strcmp(a->gid, b->gid) != 0)
+			return 1;
+	}
+
+	if(sizecheck)
+		if(a->length != b->length)
+			return 1;
+
+	if(timecheck)
+		if(a->mtime != b->mtime)
+			return 1;
+
+	if(sizecheck && timecheck)
+		return 0;
+
+	return cmpfile(a->name, b->name);
+}
+
+Dir*
+statdir(char *path)
+{
+	Dir *d;
+
+	d = dirstat(path);
+	if(d == nil)
+		error("can't stat %s: %r", path);
+	else
+		d->name = strdup(path);
+	return d;
+}
+
+Dir*
+absdir(Dir *d, char *path)
+{
+	if(d != nil)
+		d->name = smprint("%s/%s", path, d->name);
+	return d;
+}
+
+void
+cleardir(Dir *d)
+{
+	if(d != nil){
+		free(d->name);
+		d->name = "";
+	}
+}
+
+void
+freedir(Dir *d)
+{
+	cleardir(d);
+	free(d);
+}
+
+int
+dnamecmp(void *a, void *b)
+{
+	return strcmp(((Dir*)a)->name, ((Dir*)b)->name);
+}
+
+int
+readifdir(Dir **dp)
+{
+	int n, fd;
+	Dir *d;
+
+	d = *dp;
+	*dp = nil;
+	if(d == nil || (d->qid.type & QTDIR) == 0)
+		return 0;
+	fd = open(d->name, OREAD);
+	if(fd < 0){
+		error("can't open %s: %r", d->name);
+		return -1;
+	}
+	if((n = dirreadall(fd, dp)) < 0)
+		error("can't read %s: %r", d->name);
+	close(fd);
+	if(n > 1)
+		qsort(*dp, n, sizeof(Dir), dnamecmp);
+	return n;
+}
+
+void
+diffgen(Dir *ld, Dir *rd, Dir *ad, char *path);
+
+void
+diffdir(Dir *ld, Dir *rd, Dir *ad, char *path)
+{
+	int n, m, o, i, j, k, t, v;
+	char *sp, *lp, *rp, *ap;
+	Dir *od;
+
+	lp = rp = ap = nil;
+	if(ld != nil)
+		lp = ld->name;
+	if(rd != nil)
+		rp = rd->name;
+	if(ad != nil){
+		/* check if ad is the same as ld or rd */
+		if(ld != nil && samefile(ad, ld)){
+			ap = ld->name;
+			ad = nil;	/* don't read directory twice */
+		}
+		else if(rd != nil && samefile(ad, rd)){
+			ap = rd->name;
+			ad = nil;	/* don't read directory twice */
+		}
+		else
+			ap = ad->name;
+	}
+
+	n = readifdir(&ld);
+	m = readifdir(&rd);
+	if(n <= 0 && m <= 0)
+		return;
+
+	/* at least one side is directory */
+	o = readifdir(&ad);
+
+	i = j = k = 0;
+	for(;;){
+		if(i < n)
+			t = (j < m) ? strcmp(ld[i].name, rd[j].name) : -1;
+		else if(j < m)
+			t = 1;
+		else
+			break;
+
+		od = nil;
+		if(t < 0){
+			sp = smprint("%s/%s", path, ld[i].name);
+			if(ap == lp)
+				od = &ld[i];
+			else while(k < o){
+				v = strcmp(ad[k].name, ld[i].name);
+				if(v == 0){
+					od = absdir(&ad[k++], ap);
+					break;
+				} else if(v > 0)
+					break;
+				k++;
+			}
+			diffgen(absdir(&ld[i], lp), nil, od, sp);
+			cleardir(&ld[i]);
+			if(&ld[i] == od)
+				od = nil;
+			i++;
+		} else {
+			sp = smprint("%s/%s", path, rd[j].name);
+			if(ap == rp)
+				od = &rd[j];
+			else while(k < o){
+				v = strcmp(ad[k].name, rd[j].name);
+				if(v == 0){
+					od = absdir(&ad[k++], ap);
+					break;
+				} else if(v > 0)
+					break;
+				k++;
+			}
+			if(t > 0)
+				diffgen(nil, absdir(&rd[j], rp), od, sp);
+			else {
+				if(ap == lp)
+					od = &ld[i];
+				diffgen(absdir(&ld[i], lp), absdir(&rd[j], rp), od, sp);
+				cleardir(&ld[i]);
+				if(&ld[i] == od)
+					od = nil;
+				i++;
+			}
+			cleardir(&rd[j]);
+			if(&rd[j] == od)
+				od = nil;
+			j++;
+		}
+		cleardir(od);
+		free(sp);
+	}
+
+	free(ld);
+	free(rd);
+	free(ad);
+}
+
+void
+diffgen(Dir *ld, Dir *rd, Dir *ad, char *path)
+{
+	char *p;
+
+	if(dcmp(ld, rd) == 0)
+		return;
+
+	p = nil;
+	if(ld == nil || rd == nil){
+		/* one side doesnt exit anymore */
+		if(ad != nil){
+			/* existed before, is deletion */
+			if(ld != nil && (ad->qid.type & QTDIR) && (ld->qid.type & QTDIR)){
+				/* remote deleted direcotry, remote newer */
+				p = smprint("nd\t%s\n", path);
+			} else if(rd != nil && (ad->qid.type & QTDIR) && (rd->qid.type & QTDIR)){
+				/* local deleted direcotry, local newer */
+				p = smprint("dn\t%s\n", path);
+			} else if(dcmp(rd, ad) == 0){
+				/* local deleted file, local newer */
+				print("dn\t%s\n", path);
+			} else if(dcmp(ld, ad) == 0){
+				/* remote deleted file, remote newer */
+				print("nd\t%s\n", path);
+			} else if(ld != nil){
+				/* local modified, remote deleted, conflict */
+				print("md!\t%s\n", path);
+			} else {
+				/* remote modified, local deleted, conflict */
+				print("dm!\t%s\n", path);
+			}
+		} else {
+			/* didnt exist before, is addition */
+			if(ld != nil){
+				/* local added file, local newer */
+				print("an\t%s\n", path);
+			} else {
+				/* remote added file, remote newer */
+				print("na\t%s\n", path);
+			}
+		}
+	} else {
+		if(ad != nil){
+			/* existed before, is modification */
+			if((ad->qid.type & QTDIR) && (ld->qid.type & QTDIR) && (rd->qid.type & QTDIR)){
+				/* all still directories, no problem */
+			} else if(dcmp(rd, ad) == 0){
+				/* local modified file, local newer */
+				print("mn\t%s\n", path);
+			} else if(dcmp(ld, ad) == 0){
+				/* remote modified file, remote newer */
+				print("nm\t%s\n", path);
+			} else {
+				/* local and remote modified, conflict */
+				print("mm!\t%s\n", path);
+			}
+		} else {
+			/* didnt exist before, is addition from both */
+			if((ld->qid.type & QTDIR) && (rd->qid.type & QTDIR)){
+				/* local and remote added directories, no problem */
+			} else {
+				/* local and remote added files, conflict */
+				print("aa!\t%s\n", path);
+			}
+		}
+	}
+
+	diffdir(ld, rd, ad, path);
+
+	if(p != nil){
+		print("%s", p);
+		free(p);
+	}
+}
+
+void
+diff3(char *lp, char *ap, char *rp)
+{
+	Dir *ld, *rd, *ad;
+	char *name;
+
+	rd = ad = nil;
+	if((ld = statdir(lp)) == nil)
+		goto Out;
+	if((rd = statdir(rp)) == nil)
+		goto Out;
+
+	if(strcmp(ap, lp) == 0)
+		ad = ld;
+	else if(strcmp(ap, rp) == 0)
+		ad = rd;
+	else if((ad = statdir(ap)) == nil)
+		goto Out;
+	else if(samefile(ad, ld)){
+		freedir(ad);
+		ad = ld;
+	}
+	else if(samefile(ad, rd)){
+		freedir(ad);
+		ad = rd;
+	}
+
+	if(ld->qid.type & QTDIR)
+		name = ".";
+	else {
+		if(name = strrchr(lp, '/'))
+			name++;
+		else
+			name = lp;
+	}
+	diffgen(ld, rd, ad, name);
+Out:
+	freedir(ld);
+	freedir(rd);
+	if(ad != nil && ad != ld && ad != rd)
+		freedir(ad);
+}
+
+void
+usage(void)
+{
+	fprint(2, "usage: %s [ -qcutDL ] [ -p perms ] myfile oldfile yourfile\n", argv0);
+	exits("usage");
+}
+
+void
+main(int argc, char *argv[])
+{
+	ARGBEGIN {
+	case 'q':
+		quiet = 1;
+		break;
+	case 'c':
+		noerror = 1;
+		break;
+	case 'u':
+		usercheck = 1;
+		break; 
+	case 't':
+		timecheck = 1;
+		break;
+	case 'D':
+		dumpcheck = 0;
+		break;
+	case 'L':
+		sizecheck = 0;
+		break;
+	case 'p':
+		permcheck = strtol(EARGF(usage()), nil, 8) & 0777;
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if(argc != 3)
+		usage();
+
+	diff3(argv[0], argv[1], argv[2]);
+
+	if(errors)
+		exits("errors");
+
+	exits(0);
+}