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/*
* interactive diff, inspired/stolen from
* kernighan and pike, _unix programming environment_.
*/
#include <u.h>
#include <libc.h>
#include <bio.h>
int diffbflag;
int diffwflag;
void copy(Biobuf*, char*, Biobuf*, char*);
void idiff(Biobuf*, char*, Biobuf*, char*, Biobuf*, char*, Biobuf*, char*);
int opentemp(char*, int, long);
void rundiff(char*, char*, int);
void
usage(void)
{
fprint(2, "usage: idiff [-bw] file1 file2\n");
exits("usage");
}
void
main(int argc, char **argv)
{
int fd, ofd;
char diffout[40], idiffout[40];
Biobuf *b1, *b2, bdiff, bout, bstdout;
Dir *d;
ARGBEGIN{
default:
usage();
case 'b':
diffbflag++;
break;
case 'w':
diffwflag++;
break;
}ARGEND
if(argc != 2)
usage();
if((d = dirstat(argv[0])) == nil)
sysfatal("stat %s: %r", argv[0]);
if(d->mode&DMDIR)
sysfatal("%s is a directory", argv[0]);
free(d);
if((d = dirstat(argv[1])) == nil)
sysfatal("stat %s: %r", argv[1]);
if(d->mode&DMDIR)
sysfatal("%s is a directory", argv[1]);
free(d);
if((b1 = Bopen(argv[0], OREAD)) == nil)
sysfatal("open %s: %r", argv[0]);
if((b2 = Bopen(argv[1], OREAD)) == nil)
sysfatal("open %s: %r", argv[1]);
strcpy(diffout, "/tmp/idiff.XXXXXX");
fd = opentemp(diffout, ORDWR|ORCLOSE, 0);
strcpy(idiffout, "/tmp/idiff.XXXXXX");
ofd = opentemp(idiffout, ORDWR|ORCLOSE, 0);
rundiff(argv[0], argv[1], fd);
seek(fd, 0, 0);
Binit(&bdiff, fd, OREAD);
Binit(&bout, ofd, OWRITE);
idiff(b1, argv[0], b2, argv[1], &bdiff, diffout, &bout, idiffout);
Bterm(&bdiff);
Bflush(&bout);
seek(ofd, 0, 0);
Binit(&bout, ofd, OREAD);
Binit(&bstdout, 1, OWRITE);
copy(&bout, idiffout, &bstdout, "<stdout>");
exits(nil);
}
int
opentemp(char *template, int mode, long perm)
{
int fd, i;
char *p;
p = strdup(template);
if(p == nil)
sysfatal("strdup out of memory");
fd = -1;
for(i=0; i<10; i++){
mktemp(p);
if(access(p, 0) < 0 && (fd=create(p, mode, perm)) >= 0)
break;
strcpy(p, template);
}
if(fd < 0)
sysfatal("could not create temporary file");
strcpy(template, p);
free(p);
return fd;
}
void
rundiff(char *arg1, char *arg2, int outfd)
{
char *arg[10], *p;
int narg, pid;
Waitmsg *w;
narg = 0;
arg[narg++] = "/bin/diff";
arg[narg++] = "-n";
if(diffbflag)
arg[narg++] = "-b";
if(diffwflag)
arg[narg++] = "-w";
arg[narg++] = arg1;
arg[narg++] = arg2;
arg[narg] = nil;
switch(pid = fork()){
case -1:
sysfatal("fork: %r");
case 0:
dup(outfd, 1);
close(0);
exec("/bin/diff", arg);
sysfatal("exec: %r");
default:
w = wait();
if(w==nil)
sysfatal("wait: %r");
if(w->pid != pid)
sysfatal("wait got unexpected pid %d", w->pid);
if((p = strchr(w->msg, ':')) && strcmp(p, ": some") != 0)
sysfatal("%s", w->msg);
free(w);
}
}
void
runcmd(char *cmd)
{
char *arg[10];
int narg, pid, wpid;
narg = 0;
arg[narg++] = "/bin/rc";
arg[narg++] = "-c";
arg[narg++] = cmd;
arg[narg] = nil;
switch(pid = fork()){
case -1:
sysfatal("fork: %r");
case 0:
exec("/bin/rc", arg);
sysfatal("exec: %r");
default:
wpid = waitpid();
if(wpid < 0)
sysfatal("wait: %r");
if(wpid != pid)
sysfatal("wait got unexpected pid %d", wpid);
}
}
void
parse(char *s, int *pfrom1, int *pto1, int *pcmd, int *pfrom2, int *pto2)
{
*pfrom1 = *pto1 = *pfrom2 = *pto2 = 0;
s = strchr(s, ':');
if(s == nil)
sysfatal("bad diff output0");
s++;
*pfrom1 = strtol(s, &s, 10);
if(*s == ','){
s++;
*pto1 = strtol(s, &s, 10);
}else
*pto1 = *pfrom1;
if(*s++ != ' ')
sysfatal("bad diff output1");
*pcmd = *s++;
if(*s++ != ' ')
sysfatal("bad diff output2");
s = strchr(s, ':');
if(s == nil)
sysfatal("bad diff output3");
s++;
*pfrom2 = strtol(s, &s, 10);
if(*s == ','){
s++;
*pto2 = strtol(s, &s, 10);
}else
*pto2 = *pfrom2;
}
void
skiplines(Biobuf *b, char *name, int n)
{
int i;
for(i=0; i<n; i++){
while(Brdline(b, '\n')==nil){
if(Blinelen(b) <= 0)
sysfatal("early end of file on %s", name);
Bseek(b, Blinelen(b), 1);
}
}
}
void
copylines(Biobuf *bin, char *nin, Biobuf *bout, char *nout, int n)
{
char buf[4096], *p;
int i, m;
for(i=0; i<n; i++){
while((p=Brdline(bin, '\n'))==nil){
if(Blinelen(bin) <= 0)
sysfatal("early end of file on %s", nin);
m = Blinelen(bin);
if(m > sizeof buf)
m = sizeof buf;
m = Bread(bin, buf, m);
if(Bwrite(bout, buf, m) != m)
sysfatal("error writing %s: %r", nout);
}
if(Bwrite(bout, p, Blinelen(bin)) != Blinelen(bin))
sysfatal("error writing %s: %r", nout);
}
}
void
copy(Biobuf *bin, char *nin, Biobuf *bout, char *nout)
{
char buf[4096];
int m;
USED(nin);
while((m = Bread(bin, buf, sizeof buf)) > 0)
if(Bwrite(bout, buf, m) != m)
sysfatal("error writing %s: %r", nout);
}
void
idiff(Biobuf *b1, char *name1, Biobuf *b2, char *name2, Biobuf *bdiff, char *namediff, Biobuf *bout, char *nameout)
{
char buf[256], *p;
int interactive, defaultanswer, cmd, diffoffset;
int n, from1, to1, from2, to2, nf1, nf2;
Biobuf berr;
nf1 = 1;
nf2 = 1;
interactive = 1;
defaultanswer = 0;
Binit(&berr, 2, OWRITE);
while(diffoffset = Boffset(bdiff), p = Brdline(bdiff, '\n')){
p[Blinelen(bdiff)-1] = '\0';
parse(p, &from1, &to1, &cmd, &from2, &to2);
p[Blinelen(bdiff)-1] = '\n';
n = to1-from1 + to2-from2 + 1; /* #lines from diff */
if(cmd == 'c')
n += 2;
else if(cmd == 'a')
from1++;
else if(cmd == 'd')
from2++;
to1++; /* make half-open intervals */
to2++;
if(interactive){
p[Blinelen(bdiff)-1] = '\0';
fprint(2, "%s\n", p);
p[Blinelen(bdiff)-1] = '\n';
copylines(bdiff, namediff, &berr, "<stderr>", n);
Bflush(&berr);
}else
skiplines(bdiff, namediff, n);
do{
if(interactive){
fprint(2, "? ");
memset(buf, 0, sizeof buf);
if(read(0, buf, sizeof buf - 1) < 0)
sysfatal("read console: %r");
}else
buf[0] = defaultanswer;
switch(buf[0]){
case '>':
copylines(b1, name1, bout, nameout, from1-nf1);
skiplines(b1, name1, to1-from1);
skiplines(b2, name2, from2-nf2);
copylines(b2, name2, bout, nameout, to2-from2);
break;
case '<':
copylines(b1, name1, bout, nameout, to1-nf1);
skiplines(b2, name2, to2-nf2);
break;
case '=':
copylines(b1, name1, bout, nameout, from1-nf1);
skiplines(b1, name1, to1-from1);
skiplines(b2, name2, to2-nf2);
if(Bseek(bdiff, diffoffset, 0) != diffoffset)
sysfatal("seek in diff output: %r");
copylines(bdiff, namediff, bout, nameout, n+1);
break;
case '!':
runcmd(buf+1);
break;
case 'q':
if(buf[1]=='<' || buf[1]=='>' || buf[1]=='='){
interactive = 0;
defaultanswer = buf[1];
}else
fprint(2, "must be q<, q>, or q=\n");
break;
default:
fprint(2, "expect: <, >, =, q<, q>, q=, !cmd\n");
break;
}
}while(buf[0] != '<' && buf[0] != '>' && buf[0] != '=');
nf1 = to1;
nf2 = to2;
}
copy(b1, name1, bout, nameout);
}