*/ void Trim_String(REBSER *ser, REBCNT index, REBCNT len, REBCNT flags, REBVAL *with)
/*
***********************************************************************/
{
REBCNT tail = index + len;
// /all or /with
if (flags & (AM_TRIM_ALL | AM_TRIM_WITH)) {
replace_with(ser, index, tail, with);
}
// /auto option
else if (flags & AM_TRIM_AUTO) {
trim_auto(ser, index, tail);
}
// /lines option
else if (flags & AM_TRIM_LINES) {
trim_lines(ser, index, tail);
}
else {
trim_head_tail(ser, index, tail, flags & AM_TRIM_HEAD, flags & AM_TRIM_TAIL);
}
}
int main(int argc, char *argv[])
{
char *filename, *buffer;
int filelen, nlines, bufsize, tlines, nlen, fd;
char opt;
ssize_t n;
nlines = DEFAULT_LINES;
while ((opt = getopt(argc, argv, "n:")) != -1) {
switch(opt) {
case 'n':
nlines = atoi(optarg);
break;
default:
fprintf(stderr, "Usage: mtail [-n <lines>] <filename>\n");
exit(EXIT_FAILURE);
}
}
if (optind < argc) {
nlen = strlen(argv[optind]);
filename = malloc(nlen + 1);
strncpy(filename, argv[optind], nlen + 1);
fd = open(filename, O_RDONLY);
if (fd == -1) {
perror("open");
exit(EXIT_FAILURE);
}
} else {
fprintf(stderr, "Usage: mtail [-n <lines>] <filename>\n");
exit(EXIT_FAILURE);
}
if ((filelen = (int)lseek(fd, 0, SEEK_END)) == -1) {
perror("lseek");
exit(EXIT_FAILURE);
}
bufsize = BUFSIZE;
while (1) {
bufsize = min(bufsize, filelen);
if (lseek(fd, -bufsize, SEEK_END) == -1) {
perror("lseek");
exit(EXIT_FAILURE);
}
buffer = alloca(bufsize + 1);
n = read(fd, buffer, bufsize);
buffer[n] = '\0';
tlines = get_line_count(buffer);
if (tlines >= nlines || filelen == bufsize) {
if (nlines < tlines)
buffer = trim_lines(buffer, nlines, tlines);
write(STDOUT_FILENO, buffer, strlen(buffer));
break;
}
bufsize *= 2;
}
exit(EXIT_SUCCESS);
}
