src/core/show-status.c

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