Subversion Repositories planix.SVN

#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);
}