src/core/show-status.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2014 Lennart Poettering
   6
   7   systemd is free software; you can redistribute it and/or modify it
   8   under the terms of the GNU Lesser General Public License as published by
   9   the Free Software Foundation; either version 2.1 of the License, or
  10   (at your option) any later version.
  11
  12   systemd is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  19 ***/
  20
  21 #include "alloc-util.h"
  22 #include "fd-util.h"
  23 #include "io-util.h"
  24 #include "parse-util.h"
  25 #include "show-status.h"
  26 #include "string-util.h"
  27 #include "terminal-util.h"
  28 #include "util.h"
  29
  30 int parse_show_status(const char *v, ShowStatus *ret) {
  31         int r;
  32
  33         assert(v);
  34         assert(ret);
  35
  36         if (streq(v, "auto")) {
  37                 *ret = SHOW_STATUS_AUTO;
  38                 return 0;
  39         }
  40
  41         r = parse_boolean(v);
  42         if (r < 0)
  43                 return r;
  44
  45         *ret = r ? SHOW_STATUS_YES : SHOW_STATUS_NO;
  46         return 0;
  47 }
  48
  49 int status_vprintf(const char *status, bool ellipse, bool ephemeral, const char *format, va_list ap) {
  50         static const char status_indent[] = "         "; /* "[" STATUS "] " */
  51         _cleanup_free_ char *s = NULL;
  52         _cleanup_close_ int fd = -1;
  53         struct iovec iovec[6] = {};
  54         int n = 0;
  55         static bool prev_ephemeral;
  56
  57         assert(format);
  58
  59         /* This is independent of logging, as status messages are
  60          * optional and go exclusively to the console. */
  61
  62         if (vasprintf(&s, format, ap) < 0)
  63                 return log_oom();
  64
  65         /* Before you ask: yes, on purpose we open/close the console for each status line we write individually. This
  66          * is a good strategy to avoid PID 1 getting killed by the kernel's SAK concept (it doesn't fix this entirely,
  67          * but minimizes the time window the kernel might end up killing PID 1 due to SAK). It also makes things easier
  68          * for us so that we don't have to recover from hangups and suchlike triggered on the console. */
  69
  70         fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
  71         if (fd < 0)
  72                 return fd;
  73
  74         if (ellipse) {
  75                 char *e;
  76                 size_t emax, sl;
  77                 int c;
  78
  79                 c = fd_columns(fd);
  80                 if (c <= 0)
  81                         c = 80;
  82
  83                 sl = status ? sizeof(status_indent)-1 : 0;
  84
  85                 emax = c - sl - 1;
  86                 if (emax < 3)
  87                         emax = 3;
  88
  89                 e = ellipsize(s, emax, 50);
  90                 if (e) {
  91                         free(s);
  92                         s = e;
  93                 }
  94         }
  95
  96         if (prev_ephemeral)
  97                 iovec[n++] = IOVEC_MAKE_STRING("\r" ANSI_ERASE_TO_END_OF_LINE);
  98         prev_ephemeral = ephemeral;
  99
 100         if (status) {
 101                 if (!isempty(status)) {
 102                         iovec[n++] = IOVEC_MAKE_STRING("[");
 103                         iovec[n++] = IOVEC_MAKE_STRING(status);
 104                         iovec[n++] = IOVEC_MAKE_STRING("] ");
 105                 } else
 106                         iovec[n++] = IOVEC_MAKE_STRING(status_indent);
 107         }
 108
 109         iovec[n++] = IOVEC_MAKE_STRING(s);
 110         if (!ephemeral)
 111                 iovec[n++] = IOVEC_MAKE_STRING("\n");
 112
 113         if (writev(fd, iovec, n) < 0)
 114                 return -errno;
 115
 116         return 0;
 117 }
 118
 119 int status_printf(const char *status, bool ellipse, bool ephemeral, const char *format, ...) {
 120         va_list ap;
 121         int r;
 122
 123         assert(format);
 124
 125         va_start(ap, format);
 126         r = status_vprintf(status, ellipse, ephemeral, format, ap);
 127         va_end(ap);
 128
 129         return r;
 130 }