src/core/show-status.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <fcntl.h>
   4 #include <sys/stat.h>
   5 #include <sys/types.h>
   6
   7 #include "alloc-util.h"
   8 #include "fd-util.h"
   9 #include "io-util.h"
  10 #include "parse-util.h"
  11 #include "show-status.h"
  12 #include "string-table.h"
  13 #include "string-util.h"
  14 #include "terminal-util.h"
  15 #include "util.h"
  16
  17 static const char* const show_status_table[_SHOW_STATUS_MAX] = {
  18         [SHOW_STATUS_NO]        = "no",
  19         [SHOW_STATUS_ERROR]     = "error",
  20         [SHOW_STATUS_AUTO]      = "auto",
  21         [SHOW_STATUS_TEMPORARY] = "temporary",
  22         [SHOW_STATUS_YES]       = "yes",
  23 };
  24
  25 DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(show_status, ShowStatus, SHOW_STATUS_YES);
  26
  27 int parse_show_status(const char *v, ShowStatus *ret) {
  28         ShowStatus s;
  29
  30         assert(ret);
  31
  32         s = show_status_from_string(v);
  33         if (s < 0 || s == SHOW_STATUS_TEMPORARY)
  34                 return -EINVAL;
  35
  36         *ret = s;
  37         return 0;
  38 }
  39
  40 int status_vprintf(const char *status, ShowStatusFlags flags, const char *format, va_list ap) {
  41         static const char status_indent[] = "         "; /* "[" STATUS "] " */
  42         _cleanup_free_ char *s = NULL;
  43         _cleanup_close_ int fd = -1;
  44         struct iovec iovec[7] = {};
  45         int n = 0;
  46         static bool prev_ephemeral;
  47
  48         assert(format);
  49
  50         /* This is independent of logging, as status messages are
  51          * optional and go exclusively to the console. */
  52
  53         if (vasprintf(&s, format, ap) < 0)
  54                 return log_oom();
  55
  56         /* Before you ask: yes, on purpose we open/close the console for each status line we write individually. This
  57          * is a good strategy to avoid PID 1 getting killed by the kernel's SAK concept (it doesn't fix this entirely,
  58          * but minimizes the time window the kernel might end up killing PID 1 due to SAK). It also makes things easier
  59          * for us so that we don't have to recover from hangups and suchlike triggered on the console. */
  60
  61         fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
  62         if (fd < 0)
  63                 return fd;
  64
  65         if (FLAGS_SET(flags, SHOW_STATUS_ELLIPSIZE)) {
  66                 char *e;
  67                 size_t emax, sl;
  68                 int c;
  69
  70                 c = fd_columns(fd);
  71                 if (c <= 0)
  72                         c = 80;
  73
  74                 sl = status ? sizeof(status_indent)-1 : 0;
  75
  76                 emax = c - sl - 1;
  77                 if (emax < 3)
  78                         emax = 3;
  79
  80                 e = ellipsize(s, emax, 50);
  81                 if (e)
  82                         free_and_replace(s, e);
  83         }
  84
  85         if (prev_ephemeral)
  86                 iovec[n++] = IOVEC_MAKE_STRING(ANSI_REVERSE_LINEFEED "\r" ANSI_ERASE_TO_END_OF_LINE);
  87
  88         if (status) {
  89                 if (!isempty(status)) {
  90                         iovec[n++] = IOVEC_MAKE_STRING("[");
  91                         iovec[n++] = IOVEC_MAKE_STRING(status);
  92                         iovec[n++] = IOVEC_MAKE_STRING("] ");
  93                 } else
  94                         iovec[n++] = IOVEC_MAKE_STRING(status_indent);
  95         }
  96
  97         iovec[n++] = IOVEC_MAKE_STRING(s);
  98         iovec[n++] = IOVEC_MAKE_STRING("\n");
  99
 100         if (prev_ephemeral && !FLAGS_SET(flags, SHOW_STATUS_EPHEMERAL))
 101                 iovec[n++] = IOVEC_MAKE_STRING(ANSI_ERASE_TO_END_OF_LINE);
 102         prev_ephemeral = FLAGS_SET(flags, SHOW_STATUS_EPHEMERAL) ;
 103
 104         if (writev(fd, iovec, n) < 0)
 105                 return -errno;
 106
 107         return 0;
 108 }
 109
 110 int status_printf(const char *status, ShowStatusFlags flags, const char *format, ...) {
 111         va_list ap;
 112         int r;
 113
 114         assert(format);
 115
 116         va_start(ap, format);
 117         r = status_vprintf(status, flags, format, ap);
 118         va_end(ap);
 119
 120         return r;
 121 }
 122
 123 static const char* const status_unit_format_table[_STATUS_UNIT_FORMAT_MAX] = {
 124         [STATUS_UNIT_FORMAT_NAME]        = "name",
 125         [STATUS_UNIT_FORMAT_DESCRIPTION] = "description",
 126 };
 127
 128 DEFINE_STRING_TABLE_LOOKUP(status_unit_format, StatusUnitFormat);