src/core/show-status.c

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