ruby-runner.c

   1 #define _POSIX_C_SOURCE 200809L
   2 #include "ruby/internal/config.h"
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include <unistd.h>
   7 #include <sys/types.h>
   8 #include <sys/stat.h>
   9
  10 #ifdef _WIN32
  11 # error This feature is unnecessary on Windows in favor of SxS.
  12 #endif
  13
  14 #include "ruby-runner.h"
  15
  16 static void
  17 insert_env_path(const char *envname, const char *paths, size_t size, int prepend)
  18 {
  19     const char *env = getenv(envname);
  20     char c = 0;
  21     size_t n = 0;
  22
  23     if (env) {
  24         while ((c = *env) == PATH_SEP) ++env;
  25         n = strlen(env);
  26         while (n > 0 && env[n-1] == PATH_SEP) --n;
  27     }
  28     if (c) {
  29         char *e = malloc(size+n+1);
  30         size_t pos = 0;
  31         if (prepend) {
  32             if (size == n || (size < n && env[size] == PATH_SEP)) {
  33                 if (strncmp(paths, env, size) == 0) {
  34                     free(e);
  35                     return;
  36                 }
  37             }
  38             memcpy(e, paths, pos = size-1);
  39             e[pos++] = PATH_SEP;
  40         }
  41         memcpy(e+pos, env, n);
  42         pos += n;
  43         if (!prepend) {
  44             if (size == n || (size < n && env[n-size-1] == PATH_SEP)) {
  45                 if (strncmp(paths, &env[n-size], size) == 0) {
  46                     free(e);
  47                     return;
  48                 }
  49             }
  50             e[pos++] = PATH_SEP;
  51             memcpy(e+pos, paths, size-1);
  52             pos += size-1;
  53         }
  54         e[pos] = '\0';
  55         env = e;
  56     }
  57     else {
  58         env = paths;
  59     }
  60     setenv(envname, env, 1);
  61 }
  62
  63 #define EXTOUT_DIR BUILDDIR"/"EXTOUT
  64 int
  65 main(int argc, char **argv)
  66 {
  67     static const char builddir[] = BUILDDIR;
  68     static const char rubypath[] = BUILDDIR"/"STRINGIZE(RUBY_INSTALL_NAME);
  69     static const char rubylib[] =
  70         ABS_SRCDIR"/lib"
  71         PATH_SEPARATOR
  72         EXTOUT_DIR"/common"
  73         PATH_SEPARATOR
  74         EXTOUT_DIR"/"ARCH
  75         ;
  76     const size_t dirsize = sizeof(builddir);
  77     const size_t namesize = sizeof(rubypath) - dirsize;
  78     const char *rubyname = rubypath + dirsize;
  79     char *arg0 = argv[0], *p;
  80
  81     insert_env_path(LIBPATHENV, builddir, dirsize, 1);
  82     insert_env_path("RUBYLIB", rubylib, sizeof(rubylib), 0);
  83
  84     if (!(p = strrchr(arg0, '/'))) p = arg0; else p++;
  85     if (strlen(p) < namesize - 1) {
  86         argv[0] = malloc(p - arg0 + namesize);
  87         memcpy(argv[0], arg0, p - arg0);
  88         p = argv[0] + (p - arg0);
  89     }
  90     memcpy(p, rubyname, namesize);
  91
  92     execv(rubypath, argv);
  93     perror(rubypath);
  94     return -1;
  95 }