1 /* libguestfs - the guestfsd daemon
2 * Copyright (C) 2009 Red Hat Inc.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
27 #include "guestfs_protocol.h"
32 headtail (const char *prog, const char *flag, const char *n, const char *path)
39 fd = open (path, O_RDONLY);
43 reply_with_perror ("%s", path);
47 flags = COMMAND_FLAG_CHROOT_COPY_FILE_TO_STDIN | fd;
48 r = commandf (&out, &err, flags, prog, flag, n, NULL);
50 reply_with_error ("%s %s %s: %s", prog, flag, n, err);
59 /* Split it at the first whitespace. */
60 len = strcspn (out, " \t\n");
64 lines = split_lines (out);
66 if (lines == NULL) return NULL;
72 do_head (const char *path)
74 return headtail ("head", "-n", "10", path);
78 do_tail (const char *path)
80 return headtail ("tail", "-n", "10", path);
84 do_head_n (int n, const char *path)
88 snprintf (nbuf, sizeof nbuf, "%d", n);
90 return headtail ("head", "-n", nbuf, path);
94 do_tail_n (int n, const char *path)
99 snprintf (nbuf, sizeof nbuf, "%d", n);
101 snprintf (nbuf, sizeof nbuf, "+%d", -n);
103 return headtail ("tail", "-n", nbuf, path);