src/filesystem/unix/SDL_sysfilesystem.c
author Sam Lantinga <slouken@libsdl.org>
Thu, 29 Aug 2013 08:25:24 -0700
changeset 7714 1c227c5f5d8d
parent 7713 6074c53b0cda
child 7715 24f652e130fa
permissions -rw-r--r--
Christoph Mallon: Remove lone /* if */ comment.
icculus@7667
     1
/*
icculus@7667
     2
  Simple DirectMedia Layer
icculus@7667
     3
  Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>
icculus@7667
     4
icculus@7667
     5
  This software is provided 'as-is', without any express or implied
icculus@7667
     6
  warranty.  In no event will the authors be held liable for any damages
icculus@7667
     7
  arising from the use of this software.
icculus@7667
     8
icculus@7667
     9
  Permission is granted to anyone to use this software for any purpose,
icculus@7667
    10
  including commercial applications, and to alter it and redistribute it
icculus@7667
    11
  freely, subject to the following restrictions:
icculus@7667
    12
icculus@7667
    13
  1. The origin of this software must not be misrepresented; you must not
icculus@7667
    14
     claim that you wrote the original software. If you use this software
icculus@7667
    15
     in a product, an acknowledgment in the product documentation would be
icculus@7667
    16
     appreciated but is not required.
icculus@7667
    17
  2. Altered source versions must be plainly marked as such, and must not be
icculus@7667
    18
     misrepresented as being the original software.
icculus@7667
    19
  3. This notice may not be removed or altered from any source distribution.
icculus@7667
    20
*/
icculus@7667
    21
#include "SDL_config.h"
icculus@7667
    22
icculus@7667
    23
#ifdef SDL_FILESYSTEM_UNIX
icculus@7667
    24
icculus@7667
    25
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
icculus@7667
    26
/* System dependent filesystem routines                                */
icculus@7667
    27
icculus@7667
    28
#include <unistd.h>
icculus@7692
    29
#include <stdlib.h>
icculus@7668
    30
#include <sys/stat.h>
icculus@7668
    31
#include <sys/types.h>
icculus@7693
    32
#include <limits.h>
icculus@7667
    33
icculus@7692
    34
#ifdef __FREEBSD__
icculus@7692
    35
#include <sys/sysctl.h>
icculus@7692
    36
#endif
icculus@7692
    37
icculus@7667
    38
#include "SDL_error.h"
icculus@7667
    39
#include "SDL_stdinc.h"
icculus@7667
    40
#include "SDL_filesystem.h"
icculus@7667
    41
icculus@7668
    42
static char *
icculus@7668
    43
readSymLink(const char *path)
icculus@7667
    44
{
icculus@7667
    45
    char *retval = NULL;
icculus@7667
    46
    ssize_t len = 64;
icculus@7667
    47
    ssize_t rc = -1;
icculus@7667
    48
icculus@7667
    49
    while (1)
icculus@7667
    50
    {
icculus@7667
    51
        char *ptr = (char *) SDL_realloc(retval, (size_t) len);
icculus@7667
    52
        if (ptr == NULL) {
icculus@7667
    53
            SDL_OutOfMemory();
icculus@7667
    54
            break;
icculus@7667
    55
        }
icculus@7667
    56
icculus@7667
    57
        retval = ptr;
icculus@7667
    58
icculus@7667
    59
        rc = readlink(path, retval, len);
icculus@7667
    60
        if (rc == -1) {
icculus@7667
    61
            break;  /* not a symlink, i/o error, etc. */
icculus@7667
    62
        } else if (rc < len) {
icculus@7667
    63
            retval[rc] = '\0';  /* readlink doesn't null-terminate. */
icculus@7667
    64
            return retval;  /* we're good to go. */
icculus@7667
    65
        }
icculus@7667
    66
icculus@7667
    67
        len *= 2;  /* grow buffer, try again. */
icculus@7667
    68
    }
icculus@7667
    69
icculus@7667
    70
    if (retval != NULL) {
icculus@7667
    71
        SDL_free(retval);
icculus@7667
    72
    }
icculus@7667
    73
    return NULL;
icculus@7667
    74
}
icculus@7667
    75
icculus@7667
    76
icculus@7667
    77
char *
icculus@7667
    78
SDL_GetBasePath(void)
icculus@7667
    79
{
icculus@7667
    80
    char *retval = NULL;
icculus@7667
    81
icculus@7692
    82
#if defined(__FREEBSD__)
icculus@7692
    83
    char fullpath[PATH_MAX];
icculus@7692
    84
    size_t buflen = sizeof (fullpath);
icculus@7697
    85
    const int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
icculus@7692
    86
    if (sysctl(mib, 4, fullpath, &buflen, NULL, 0) != -1) {
icculus@7692
    87
        retval = SDL_strdup(fullpath);
icculus@7692
    88
        if (!retval) {
icculus@7692
    89
            SDL_OutOfMemory();
icculus@7692
    90
            return NULL;
icculus@7692
    91
        }
icculus@7692
    92
    }
icculus@7692
    93
#elif defined(__SOLARIS__)
icculus@7692
    94
    const char *path = getexecname();
icculus@7692
    95
    if ((path != NULL) && (path[0] == '/')) { /* must be absolute path... */
icculus@7694
    96
        retval = SDL_strdup(path);
icculus@7692
    97
        if (!retval) {
icculus@7692
    98
            SDL_OutOfMemory();
icculus@7692
    99
            return NULL;
icculus@7692
   100
        }
icculus@7692
   101
    }
icculus@7692
   102
#endif
icculus@7692
   103
icculus@7667
   104
    /* is a Linux-style /proc filesystem available? */
icculus@7692
   105
    if (!retval && (access("/proc", F_OK) == 0)) {
icculus@7692
   106
        #if defined(__FREEBSD__)
icculus@7692
   107
        retval = readSymLink("/proc/curproc/file");
icculus@7692
   108
        #elif defined(__NETBSD__)
icculus@7692
   109
        retval = readSymLink("/proc/curproc/exe");
icculus@7692
   110
        #else
icculus@7692
   111
        retval = readSymLink("/proc/self/exe");  /* linux. */
icculus@7692
   112
        #endif
icculus@7667
   113
        if (retval == NULL) {
icculus@7667
   114
            /* older kernels don't have /proc/self ... try PID version... */
icculus@7667
   115
            char path[64];
icculus@7667
   116
            const int rc = (int) SDL_snprintf(path, sizeof(path),
icculus@7667
   117
                                              "/proc/%llu/exe",
icculus@7667
   118
                                              (unsigned long long) getpid());
icculus@7667
   119
            if ( (rc > 0) && (rc < sizeof(path)) ) {
icculus@7667
   120
                retval = readSymLink(path);
icculus@7667
   121
            }
icculus@7667
   122
        }
icculus@7667
   123
    }
icculus@7667
   124
icculus@7667
   125
    /* If we had access to argv[0] here, we could check it for a path,
icculus@7667
   126
        or troll through $PATH looking for it, too. */
icculus@7667
   127
icculus@7667
   128
    if (retval != NULL) { /* chop off filename. */
icculus@7667
   129
        char *ptr = SDL_strrchr(retval, '/');
icculus@7667
   130
        if (ptr != NULL) {
icculus@7667
   131
            *(ptr+1) = '\0';
icculus@7667
   132
        } else {  /* shouldn't happen, but just in case... */
icculus@7667
   133
            SDL_free(retval);
icculus@7667
   134
            retval = NULL;
icculus@7667
   135
        }
icculus@7667
   136
    }
icculus@7667
   137
icculus@7667
   138
    if (retval != NULL) {
icculus@7667
   139
        /* try to shrink buffer... */
icculus@7667
   140
        char *ptr = (char *) SDL_realloc(retval, strlen(retval) + 1);
icculus@7667
   141
        if (ptr != NULL)
icculus@7667
   142
            retval = ptr;  /* oh well if it failed. */
icculus@7667
   143
    }
icculus@7667
   144
icculus@7667
   145
    return retval;
icculus@7667
   146
}
icculus@7667
   147
icculus@7667
   148
char *
icculus@7667
   149
SDL_GetPrefPath(const char *org, const char *app)
icculus@7667
   150
{
icculus@7667
   151
    /*
icculus@7667
   152
     * We use XDG's base directory spec, even if you're not on Linux.
icculus@7667
   153
     *  This isn't strictly correct, but the results are relatively sane
icculus@7667
   154
     *  in any case.
icculus@7667
   155
     *
icculus@7667
   156
     * http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
icculus@7667
   157
     */
icculus@7667
   158
    const char *envr = SDL_getenv("XDG_DATA_HOME");
slouken@7713
   159
    const char *append;
icculus@7667
   160
    char *retval = NULL;
icculus@7667
   161
    char *ptr = NULL;
icculus@7667
   162
    size_t len = 0;
icculus@7667
   163
icculus@7667
   164
    if (!envr) {
icculus@7667
   165
        /* You end up with "$HOME/.local/share/Game Name 2" */
icculus@7667
   166
        envr = SDL_getenv("HOME");
icculus@7667
   167
        if (!envr) {
icculus@7667
   168
            /* we could take heroic measures with /etc/passwd, but oh well. */
icculus@7667
   169
            SDL_SetError("neither XDG_DATA_HOME nor HOME environment is set");
icculus@7667
   170
            return NULL;
icculus@7667
   171
        }
slouken@7713
   172
        append = "/.local/share/";
urkle@7695
   173
    } else {
slouken@7713
   174
        append = "/";
slouken@7714
   175
    }
icculus@7667
   176
slouken@7713
   177
    len = SDL_strlen(envr);
slouken@7713
   178
    if (envr[len - 1] == '/')
slouken@7713
   179
        append += 1;
slouken@7713
   180
slouken@7713
   181
    len += SDL_strlen(append) + SDL_strlen(app) + 2;
icculus@7667
   182
    retval = (char *) SDL_malloc(len);
icculus@7667
   183
    if (!retval) {
icculus@7667
   184
        SDL_OutOfMemory();
icculus@7667
   185
        return NULL;
icculus@7667
   186
    }
icculus@7667
   187
icculus@7667
   188
    SDL_snprintf(retval, len, "%s%s%s/", envr, append, app);
icculus@7667
   189
icculus@7667
   190
    for (ptr = retval+1; *ptr; ptr++) {
icculus@7667
   191
        if (*ptr == '/') {
icculus@7667
   192
            *ptr = '\0';
icculus@7667
   193
            mkdir(retval, 0700);
icculus@7667
   194
            *ptr = '/';
icculus@7667
   195
        }
icculus@7667
   196
    }
icculus@7667
   197
    mkdir(retval, 0700);
icculus@7667
   198
icculus@7667
   199
    return retval;
icculus@7667
   200
}
icculus@7667
   201
icculus@7667
   202
#endif /* SDL_FILESYSTEM_UNIX */
icculus@7667
   203
icculus@7667
   204
/* vi: set ts=4 sw=4 expandtab: */