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#include <u.h>
#include <libc.h>
int multi;
int nlines;
char *status = nil;
int
line(int fd, char *file)
{
char c;
int m, n, nalloc;
char *buf;
nalloc = 0;
buf = nil;
for(m=0; ; ){
n = read(fd, &c, 1);
if(n < 0){
fprint(2, "read: error reading %s: %r\n", file);
exits("read error");
}
if(n == 0){
if(m == 0)
status = "eof";
break;
}
if(m == nalloc){
nalloc += 1024;
buf = realloc(buf, nalloc);
if(buf == nil){
fprint(2, "read: malloc error: %r\n");
exits("malloc");
}
}
buf[m++] = c;
if(c == '\n')
break;
}
if(m > 0)
write(1, buf, m);
free(buf);
return m;
}
void
lines(int fd, char *file)
{
do{
if(line(fd, file) == 0)
break;
}while(multi || --nlines>0);
}
void
main(int argc, char *argv[])
{
int i, fd;
char *s;
ARGBEGIN{
case 'm':
multi = 1;
break;
case 'n':
s = ARGF();
if(s){
nlines = atoi(s);
break;
}
/* fall through */
default:
fprint(2, "usage: read [-m] [-n nlines] [files...]\n");
exits("usage");
}ARGEND
if(argc == 0)
lines(0, "<stdin>");
else
for(i=0; i<argc; i++){
fd = open(argv[i], OREAD);
if(fd < 0){
fprint(2, "read: can't open %s: %r\n", argv[i]);
exits("open");
}
lines(fd, argv[i]);
close(fd);
}
exits(status);
}
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