ref: 51cad53e4b70b6d9fcbbbbf6530f8d7cc3d7f7cb
parent: a0e420b2e38e80b1aa36131332d1f3e8516782c9
author: qwx <[email protected]>
date: Wed Jul 26 21:28:18 EDT 2023
pcmmix: really fix truncation to stdin buffer size
--- a/pcmmix.c
+++ b/pcmmix.c
@@ -10,7 +10,6 @@
int fd;
char *path;
int n;
- int Δ;
uchar buf[Bufsz];
};
void
@@ -23,7 +22,7 @@
void
main(int argc, char **argv)
{- int n, m, notrunc, gotem;
+ int m, max, notrunc;
double f;
File *ftab, *fp;
uchar u[Bufsz], *p, *q;
@@ -42,55 +41,39 @@
if((ftab = mallocz(nf * sizeof *ftab, 1)) == nil)
sysfatal("mallocz: %r");fp = ftab;
- (fp++)->path = "stdin";
- while(*argv != nil){+ fp->path = "/fd/0";
+ if((d = dirfstat(0)) == nil)
+ sysfatal("dirfstat: %r");+ m = d->length;
+ free(d);
+ fp->fd = m > 0 ? 0 : -1;
+ for(fp++; *argv!=nil; fp++){if((fp->fd = open(*argv, OREAD)) < 0)
sysfatal("open: %r");- (fp++)->path = *argv++;
+ fp->path = *argv++;
}
- gotem = 0;
for(;;){- n = 0;
+ max = sizeof ftab[0].buf;
for(fp=ftab; fp<ftab+nf; fp++){if(fp->fd < 0)
continue;
- if(fp == ftab){- if((d = dirfstat(0)) == nil)
- sysfatal("dirfstat: %r");- m = d->length;
- free(d);
- if(m > 0)
- gotem = 1;
- else if(gotem){- if(!notrunc)
- exits(nil);
- fp->fd = -1;
- continue;
- }
- }
- m = sizeof fp->buf - fp->Δ;
- if(m < 0)
- m = sizeof fp->buf;
- if(n > 0 && n < m)
- m = n;
- fp->n = read(fp->fd, fp->buf+fp->Δ, m);
- if(n == 0 || notrunc && n < fp->n || !notrunc && n > fp->n)
- n = fp->n;
- if(fp->n > 0)
+ fp->n = read(fp->fd, fp->buf, max);
+ if(fp->n > 0){+ if(fp == ftab)
+ max = fp->n;
continue;
+ }
fp->fd = -1;
- if(!notrunc)
- exits(nil);
if(fp->n < 0)
fprint(2, "read %s: %r\n", fp->path);
+ if(fp == ftab && !notrunc)
+ goto end;
}
- if(n <= 0)
- break;
- memset(u, 0, n);
+ memset(u, 0, max);
for(fp=ftab; fp<ftab+nf; fp++){if(fp->fd < 0)
continue;
- for(p=u, q=fp->buf; q<fp->buf+n; p+=2, q+=2){+ for(p=u, q=fp->buf; q<fp->buf+fp->n; p+=2, q+=2){v = (s16int)(q[1] << 8 | q[0]);
v *= f;
v += (s16int)(p[1] << 8 | p[0]);
@@ -101,9 +84,9 @@
p[0] = v;
p[1] = v >> 8;
}
- fp->Δ = n < fp->n ? fp->n - n : 0;
}
- write(1, u, n);
+ write(1, u, max);
}
+end:
exits(nil);
}