Biobuf stdout;

#include <u.h>
#include <libc.h>
#include <bio.h>
#include "diff.h"

#define DIRECTORY(s) ((s)->qid.type&QTDIR)
#define REGULAR_FILE(s) ((s)->type == 'M' && !DIRECTORY(s))

Biobuf stdout;

static char *tmp[] = {"/tmp/diff1XXXXXXXXXXX", "/tmp/diff2XXXXXXXXXXX"};
static int whichtmp;
static char *progname;
static char usage[] = "diff [-abcefmnrw] file1 ... file2\n";

static void
rmtmpfiles(void)
{
while (whichtmp > 0) {
whichtmp--;
remove(tmp[whichtmp]);
}
}

void
done(int status)
{
rmtmpfiles();
switch(status)
{
case 0:
exits("");
case 1:
exits("some");
default:
exits("error");
}
/*NOTREACHED*/
}

void
panic(int status, char *fmt, ...)
{
va_list arg;

Bflush(&stdout);

fprint(2, "%s: ", progname);
va_start(arg, fmt);
vfprint(2, fmt, arg);
va_end(arg);
if (status)
done(status);
/*NOTREACHED*/
}

static int
catch(void *a, char *msg)
{
USED(a);
panic(2, msg);
return 1;
}

int
mkpathname(char *pathname, char *path, char *name)
{
if (strlen(path) + strlen(name) > MAXPATHLEN) {
panic(0, "pathname %s/%s too long\n", path, name);
return 1;
}
sprint(pathname, "%s/%s", path, name);
return 0;
}

static char *
mktmpfile(int input, Dir **sb)
{
int fd, i;
char *p;
char buf[8192];

atnotify(catch, 1);
p = mktemp(tmp[whichtmp++]);
fd = create(p, OWRITE, 0600);
if (fd < 0) {
panic(mflag ? 0: 2, "cannot create %s: %r\n", p);
return 0;
}
while ((i = read(input, buf, sizeof(buf))) > 0) {
if ((i = write(fd, buf, i)) < 0)
break;
}
*sb = dirfstat(fd);
close(fd);
if (i < 0) {
panic(mflag ? 0: 2, "cannot read/write %s: %r\n", p);
return 0;
}
return p;
}

static char *
statfile(char *file, Dir **sb)
{
Dir *dir;
int input;

dir = dirstat(file);
if(dir == nil) {
if (strcmp(file, "-") || (dir = dirfstat(0)) == nil) {
panic(mflag ? 0: 2, "cannot stat %s: %r\n", file);
return 0;
}
free(dir);
return mktmpfile(0, sb);
}
else if (!REGULAR_FILE(dir) && !DIRECTORY(dir)) {
free(dir);
if ((input = open(file, OREAD)) == -1) {
panic(mflag ? 0: 2, "cannot open %s: %r\n", file);
return 0;
}
file = mktmpfile(input, sb);
close(input);
}
else
*sb = dir;
return file;
}

void
diff(char *f, char *t, int level)
{
char *fp, *tp, *p, fb[MAXPATHLEN+1], tb[MAXPATHLEN+1];
Dir *fsb, *tsb;

if ((fp = statfile(f, &fsb)) == 0)
goto Return;
if ((tp = statfile(t, &tsb)) == 0){
free(fsb);
goto Return;
}
if (DIRECTORY(fsb) && DIRECTORY(tsb)) {
if (rflag || level == 0)
diffdir(fp, tp, level);
else
Bprint(&stdout, "Common subdirectories: %s and %s\n",
fp, tp);
}
else if (REGULAR_FILE(fsb) && REGULAR_FILE(tsb))
diffreg(fp, tp);
else {
if (REGULAR_FILE(fsb)) {
if ((p = utfrrune(f, '/')) == 0)
p = f;
else
p++;
if (mkpathname(tb, tp, p) == 0)
diffreg(fp, tb);
}
else {
if ((p = utfrrune(t, '/')) == 0)
p = t;
else
p++;
if (mkpathname(fb, fp, p) == 0)
diffreg(fb, tp);
}
}
free(fsb);
free(tsb);
Return:
rmtmpfiles();
}

void
main(int argc, char *argv[])
{
char *p;
int i;
Dir *fsb, *tsb;

Binit(&stdout, 1, OWRITE);
progname = argv0 = *argv;
while (--argc && (*++argv)[0] == '-' && (*argv)[1]) {
for (p = *argv+1; *p; p++) {
switch (*p) {

case 'e':
case 'f':
case 'n':
case 'c':
case 'a':
mode = *p;
break;

case 'w':
bflag = 2;
break;

case 'b':
bflag = 1;
break;

case 'r':
rflag = 1;
break;

case 'm':
mflag = 1;
break;

case 'h':
default:
progname = "Usage";
panic(2, usage);
}
}
}
if (argc < 2)
panic(2, usage, progname);
if ((tsb = dirstat(argv[argc-1])) == nil)
panic(2, "can't stat %s\n", argv[argc-1]);
if (argc > 2) {
if (!DIRECTORY(tsb))
panic(2, usage, progname);
mflag = 1;
}
else {
if ((fsb = dirstat(argv[0])) == nil)
panic(2, "can't stat %s\n", argv[0]);
if (DIRECTORY(fsb) && DIRECTORY(tsb))
mflag = 1;
free(fsb);
}
free(tsb);
for (i = 0; i < argc-1; i++)
diff(argv[i], argv[argc-1], 0);
done(anychange);
/*NOTREACHED*/
}

static char noroom[] = "out of memory - try diff -h\n";

void *
emalloc(unsigned n)
{
register void *p;

if ((p = malloc(n)) == 0)
panic(2, noroom);
return p;
}

void *
erealloc(void *p, unsigned n)
{
register void *rp;

if ((rp = realloc(p, n)) == 0)
panic(2, noroom);
return rp;
}