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src/os/unix/ngx_setproctitle.c - nginx-1.7.10

Global variables defined

Functions defined

Source code


  2. /*
  3. * Copyright (C) Igor Sysoev
  4. * Copyright (C) Nginx, Inc.
  5. */


  8. #include <ngx_config.h>
  9. #include <ngx_core.h>


  12. #if (NGX_SETPROCTITLE_USES_ENV)

  14. /*
  15. * To change the process title in Linux and Solaris we have to set argv[1]
  16. * to NULL and to copy the title to the same place where the argv[0] points to.
  17. * However, argv[0] may be too small to hold a new title.  Fortunately, Linux
  18. * and Solaris store argv[] and environ[] one after another.  So we should
  19. * ensure that is the continuous memory and then we allocate the new memory
  20. * for environ[] and copy it.  After this we could use the memory starting
  21. * from argv[0] for our process title.
  22. *
  23. * The Solaris's standard /bin/ps does not show the changed process title.
  24. * You have to use "/usr/ucb/ps -w" instead.  Besides, the UCB ps does not
  25. * show a new title if its length less than the origin command line length.
  26. * To avoid it we append to a new title the origin command line in the
  27. * parenthesis.
  28. */

  30. extern char **environ;

  32. ‌static char *ngx_os_argv_last;

  34. ngx_int_t
  35. ‌ngx_init_setproctitle(ngx_log_t *log)
  36. {
  37.     u_char      *p;
  38.     size_t       size;
  39.     ngx_uint_t   i;

  41.     size = 0;

  43.     for (i = 0; environ[i]; i++) {
  44.         size += ngx_strlen(environ[i]) + 1;
  45.     }

  47.     p = ngx_alloc(size, log);
  48.     if (p == NULL) {
  49.         return NGX_ERROR;
  50.     }

  52.     ngx_os_argv_last = ngx_os_argv[0];

  54.     for (i = 0; ngx_os_argv[i]; i++) {
  55.         if (ngx_os_argv_last == ngx_os_argv[i]) {
  56.             ngx_os_argv_last = ngx_os_argv[i] + ngx_strlen(ngx_os_argv[i]) + 1;
  57.         }
  58.     }

  60.     for (i = 0; environ[i]; i++) {
  61.         if (ngx_os_argv_last == environ[i]) {

  63.             size = ngx_strlen(environ[i]) + 1;
  64.             ngx_os_argv_last = environ[i] + size;

  66.             ngx_cpystrn(p, (u_char *) environ[i], size);
  67.             environ[i] = (char *) p;
  68.             p += size;
  69.         }
  70.     }

  72.     ngx_os_argv_last--;

  74.     return NGX_OK;
  75. }


  78. void
  79. ‌ngx_setproctitle(char *title)
  80. {
  81.     u_char     *p;

  83. #if (NGX_SOLARIS)

  85.     ngx_int_t   i;
  86.     size_t      size;

  88. #endif

  90.     ngx_os_argv[1] = NULL;

  92.     p = ngx_cpystrn((u_char *) ngx_os_argv[0], (u_char *) "nginx: ",
  93.                     ngx_os_argv_last - ngx_os_argv[0]);

  95.     p = ngx_cpystrn(p, (u_char *) title, ngx_os_argv_last - (char *) p);

  97. #if (NGX_SOLARIS)

  99.     size = 0;

  101.     for (i = 0; i < ngx_argc; i++) {
  102.         size += ngx_strlen(ngx_argv[i]) + 1;
  103.     }

  105.     if (size > (size_t) ((char *) p - ngx_os_argv[0])) {

  107.         /*
  108.          * ngx_setproctitle() is too rare operation so we use
  109.          * the non-optimized copies
  110.          */

  112.         p = ngx_cpystrn(p, (u_char *) " (", ngx_os_argv_last - (char *) p);

  114.         for (i = 0; i < ngx_argc; i++) {
  115.             p = ngx_cpystrn(p, (u_char *) ngx_argv[i],
  116.                             ngx_os_argv_last - (char *) p);
  117.             p = ngx_cpystrn(p, (u_char *) " ", ngx_os_argv_last - (char *) p);
  118.         }

  120.         if (*(p - 1) == ' ') {
  121.             *(p - 1) = ')';
  122.         }
  123.     }

  125. #endif

  127.     if (ngx_os_argv_last - (char *) p) {
  128.         ngx_memset(p, NGX_SETPROCTITLE_PAD, ngx_os_argv_last - (char *) p);
  129.     }

  131.     ngx_log_debug1(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0,
  132.                    "setproctitle: \"%s\"", ngx_os_argv[0]);
  133. }

  135. #endif /* NGX_SETPROCTITLE_USES_ENV */

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