src/core/show-status.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   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_AUTO] = "auto",
  20         [SHOW_STATUS_TEMPORARY] = "temporary",
  21         [SHOW_STATUS_YES] = "yes",
  22 };
  23
  24 DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(show_status, ShowStatus, SHOW_STATUS_YES);
  25
  26 int parse_show_status(const char *v, ShowStatus *ret) {
  27         ShowStatus s;
  28
  29         assert(ret);
  30
  31         s = show_status_from_string(v);
  32         if (s < 0 || s == SHOW_STATUS_TEMPORARY)
  33                 return -EINVAL;
  34
  35         *ret = s;
  36         return 0;
  37 }
  38
  39 int status_vprintf(const char *status, ShowStatusFlags flags, const char *format, va_list ap) {
  40         static const char status_indent[] = "         "; /* "[" STATUS "] " */
  41         _cleanup_free_ char *s = NULL;
  42         _cleanup_close_ int fd = -1;
  43         struct iovec iovec[7] = {};
  44         int n = 0;
  45         static bool prev_ephemeral;
  46
  47         assert(format);
  48
  49         /* This is independent of logging, as status messages are
  50          * optional and go exclusively to the console. */
  51
  52         if (vasprintf(&s, format, ap) < 0)
  53                 return log_oom();
  54
  55         /* Before you ask: yes, on purpose we open/close the console for each status line we write individually. This
  56          * is a good strategy to avoid PID 1 getting killed by the kernel's SAK concept (it doesn't fix this entirely,
  57          * but minimizes the time window the kernel might end up killing PID 1 due to SAK). It also makes things easier
  58          * for us so that we don't have to recover from hangups and suchlike triggered on the console. */
  59
  60         fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
  61         if (fd < 0)
  62                 return fd;
  63
  64         if (FLAGS_SET(flags, SHOW_STATUS_ELLIPSIZE)) {
  65                 char *e;
  66                 size_t emax, sl;
  67                 int c;
  68
  69                 c = fd_columns(fd);
  70                 if (c <= 0)
  71                         c = 80;
  72
  73                 sl = status ? sizeof(status_indent)-1 : 0;
  74
  75                 emax = c - sl - 1;
  76                 if (emax < 3)
  77                         emax = 3;
  78
  79                 e = ellipsize(s, emax, 50);
  80                 if (e)
  81                         free_and_replace(s, e);
  82         }
  83
  84         if (prev_ephemeral)
  85                 iovec[n++] = IOVEC_MAKE_STRING(ANSI_REVERSE_LINEFEED "\r" ANSI_ERASE_TO_END_OF_LINE);
  86
  87         if (status) {
  88                 if (!isempty(status)) {
  89                         iovec[n++] = IOVEC_MAKE_STRING("[");
  90                         iovec[n++] = IOVEC_MAKE_STRING(status);
  91                         iovec[n++] = IOVEC_MAKE_STRING("] ");
  92                 } else
  93                         iovec[n++] = IOVEC_MAKE_STRING(status_indent);
  94         }
  95
  96         iovec[n++] = IOVEC_MAKE_STRING(s);
  97         iovec[n++] = IOVEC_MAKE_STRING("\n");
  98
  99         if (prev_ephemeral && !FLAGS_SET(flags, SHOW_STATUS_EPHEMERAL))
 100                 iovec[n++] = IOVEC_MAKE_STRING(ANSI_ERASE_TO_END_OF_LINE);
 101         prev_ephemeral = FLAGS_SET(flags, SHOW_STATUS_EPHEMERAL) ;
 102
 103         if (writev(fd, iovec, n) < 0)
 104                 return -errno;
 105
 106         return 0;
 107 }
 108
 109 int status_printf(const char *status, ShowStatusFlags flags, const char *format, ...) {
 110         va_list ap;
 111         int r;
 112
 113         assert(format);
 114
 115         va_start(ap, format);
 116         r = status_vprintf(status, flags, format, ap);
 117         va_end(ap);
 118
 119         return r;
 120 }