A version of our operating system interface suitable for POSIX-compliant operating systems.
§1. The C standard library leaves many questions unanswered about how to deal with the host operating system: for example, it knows very little about directories, or about concurrency. The POSIX standard ("Portable Operating System Interface") aims to fill these gaps by providing facilities which ought to exist across any Unix-like system. POSIX is neither fully present on Unix-like systems nor fully absent from Windows, but for the limited purposes we need here, it's simplest to divide all operating systems into two groups: the POSIX group, and Windows.
This Foundation module therefore comes with two variant versions of the
Platform:: section of code. The one you're reading compiles on a POSIX
operating system, and the other one on Windows.
This paragraph is used only if PLATFORM_POSIX is defined.
§2. Some basics that apply to all POSIX-supporting systems.
define FOLDER_SEPARATOR '/'
define SHELL_QUOTE_CHARACTER '\''
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>
#include <dirent.h>
#include <pthread.h>
#include <limits.h>
#include <unistd.h>
This paragraph is used only if PLATFORM_POSIX is defined.
define PLATFORM_STRING "macos"
define SHELL_QUOTE_CHARACTER '\''
define INFORM_FOLDER_RELATIVE_TO_HOME "Library"
This paragraph is used only if PLATFORM_MACOSX and PLATFORM_POSIX are defined.
§4. Generic Unix. These settings are used both for the Linux versions (both command-line, by Adam Thornton, and for Ubuntu, Fedora, Debian and so forth, by Philip Chimento) and also for Solaris variants: they can probably be used for any Unix-based system.
define PLATFORM_STRING "unix"
define INFORM_FOLDER_RELATIVE_TO_HOME ""
#include <strings.h>
This paragraph is used only if PLATFORM_UNIX and PLATFORM_POSIX are defined.
§5. Linux. These settings are used both for the Linux versions (both command-line, by Adam Thornton, and for Ubuntu, Fedora, Debian and so forth, by Philip Chimento) and also for Solaris variants: they can probably be used for any Unix-based system.
define PLATFORM_STRING "linux"
define INFORM_FOLDER_RELATIVE_TO_HOME ""
#include <strings.h>
This paragraph is used only if PLATFORM_LINUX and PLATFORM_POSIX are defined.
§6. Android. These settings are used for Nathan Summers's Android versions.
define PLATFORM_STRING "android"
define SUPPRESS_MAIN
define INFORM_FOLDER_RELATIVE_TO_HOME ""
#include <strings.h>
This paragraph is used only if PLATFORM_ANDROID and PLATFORM_POSIX are defined.
§7. Locale. The following definition handles possible differences of text encoding in filenames, which depend on the current "locale". Locale is an odd piece of old Unix terminology, but one thing it includes is how the textual names of files are encoded (as ASCII, as ISO Latin-1, as UTF-8, etc.). The default here is UTF-8 since OS X and Linux both adopt this.
#ifndef LOCALE_IS_ISO
#ifndef LOCALE_IS_UTF8
#define LOCALE_IS_UTF8 1
#endif
#endif
This paragraph is used only if PLATFORM_POSIX is defined.
char *Platform::getenv(const char *name) {
return getenv(name);
}
This paragraph is used only if PLATFORM_POSIX is defined.
The function Platform::getenv is used in 1/wp (§4), 3/pth (§2, §3).
§9. Executable location. Fill the wide-char buffer p with the path to the current executable, up to
length length. This function is guaranteed to be called from only one
thread. Should the information be unavailable, or fail to fit into p,
truncate p to zero length. (On some platforms, the information will
always be unavailable: that doesn't mean we can't run on those platforms,
just that installation and use of Foundation-built tools is less convenient.)
void Platform::where_am_i(wchar_t *p, size_t length) {
char buffer[PATH_MAX + 1];
<Follow the proc filesystem symlink to the real filesystem's file 9.1>;
<Transcode buffer, which is locale-encoded, into the wide-char buffer 9.2>;
}
This paragraph is used only if PLATFORM_LINUX and PLATFORM_POSIX are defined.
The function Platform::where_am_i is used in §10, 1/wp (§5), 3/pth (§3).
§9.1. On Linux, /proc/self/exe is a symlink to the current process's executable.
Follow that link to find the path. Normally when reading a symlink, one uses
lstat() to find the path length instead of guessing PATH_MAX, but the
symlinks in /proc are special and don't provide a length to lstat().
<Follow the proc filesystem symlink to the real filesystem's file 9.1> =
ssize_t link_len = readlink("/proc/self/exe", buffer, PATH_MAX);
if (link_len < 0) <Fail 9.1.1>; unable to find
buffer[link_len] = '\0';
This paragraph is used only if PLATFORM_POSIX is defined.
This code is used in §9.
§9.2. Next, convert the obtained buffer (which is a string in the local filename encoding, and possibly in a multibyte encoding such as UTF-8) to a wide-char string.
<Transcode buffer, which is locale-encoded, into the wide-char buffer 9.2> =
size_t convert_len = mbstowcs(p, buffer, length);
if (convert_len == (size_t)-1) <Fail 9.1.1>; wouldn't fit
This paragraph is used only if PLATFORM_POSIX is defined.
This code is used in §9.
p[0] = '\0';
return;
This paragraph is used only if PLATFORM_POSIX is defined.
This code is used in §9.1, §9.2.
void Platform::where_am_i(wchar_t *p, size_t length) {
p[0] = 0;
}
This paragraph is used only if PLATFORM_POSIX is defined and if PLATFORM_LINUX is undefined.
The function Platform::where_am_i is used in §9, 1/wp (§5), 3/pth (§3).
int Platform::system(const char *cmd) {
return system(cmd);
}
This paragraph is used only if PLATFORM_POSIX is defined.
The function Platform::system is used in 1/wp (§6), 3/shl (§5).
int Platform::mkdir(char *transcoded_pathname) {
errno = 0;
int rv = mkdir(transcoded_pathname, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
if (rv == 0) return TRUE;
if (errno == EEXIST) return TRUE;
return FALSE;
}
void *Platform::opendir(char *path_to_folder) {
DIR *dirp = opendir(path_to_folder);
return (void *) dirp;
}
int Platform::readdir(void *folder, char *path_to_folder, char *leafname) {
char path_to[2*MAX_FILENAME_LENGTH+2];
struct stat file_status;
int rv;
DIR *dirp = (DIR *) folder;
struct dirent *dp;
if ((dp = readdir(dirp)) == NULL) return FALSE;
sprintf(path_to, "%s%c%s", path_to_folder, FOLDER_SEPARATOR, dp->d_name);
rv = stat(path_to, &file_status);
if (rv != 0) return FALSE;
if (S_ISDIR(file_status.st_mode)) sprintf(leafname, "%s/", dp->d_name);
else strcpy(leafname, dp->d_name);
return TRUE;
}
void Platform::closedir(void *folder) {
DIR *dirp = (DIR *) folder;
closedir(dirp);
}
This paragraph is used only if PLATFORM_POSIX is defined.
The function Platform::mkdir is used in 1/wp (§7), 3/pth (§8).
The function Platform::opendir is used in 1/wp (§7), 3/drc (§2).
The function Platform::readdir is used in 1/wp (§7), 3/drc (§2).
The function Platform::closedir is used in 1/wp (§7), 3/drc (§2).
void Platform::sleep(int seconds) {
sleep((unsigned int) seconds);
}
This paragraph is used only if PLATFORM_POSIX is defined.
The function Platform::sleep is used in 1/wp (§8).
§14. Notifications. The "submarine" sound is a gloomy thunk; the "bell" is the three-tone rising alert noise which iPhones make when they receive texts, but which hackers of a certain age will remember as the "I have ripped your music CD now" alert from SoundJam, the program which Apple bought and rebranded as iTunes. Apple now seems to consider this alert a general-purpose "something good has happened".
It is anybody's guess how long Apple will permit the shell command osascript
to survive, given the MacOS team's current hostility to scripting; we're
actually running a one-line AppleScript here.
void Platform::notification(text_stream *text, int happy) {
char *sound_name = "Bell.aiff";
if (happy == FALSE) sound_name = "Submarine.aiff";
TEMPORARY_TEXT(TEMP)
WRITE_TO(TEMP, "osascript -e 'display notification \"%S\" "
"sound name \"%s\" with title \"intest Results\"'", text, sound_name);
Shell::run(TEMP);
DISCARD_TEXT(TEMP)
}
This paragraph is used only if PLATFORM_MACOSX and PLATFORM_POSIX are defined.
The function Platform::notification is used in §15, 1/wp (§9).
void Platform::notification(text_stream *text, int happy) {
}
This paragraph is used only if PLATFORM_POSIX is defined and if PLATFORM_MACOSX is undefined.
The function Platform::notification is used in §14, 1/wp (§9).
typedef pthread_t foundation_thread;
typedef pthread_attr_t foundation_thread_attributes;
This paragraph is used only if PLATFORM_POSIX is defined.
int Platform::create_thread(foundation_thread *pt,
const foundation_thread_attributes *pa, void *(*fn)(void *), void *arg) {
return pthread_create(pt, pa, fn, arg);
}
int Platform::join_thread(pthread_t pt, void** rv) {
return pthread_join(pt, rv);
}
void Platform::init_thread(pthread_attr_t* pa, size_t size) {
pthread_attr_init(pa);
pthread_attr_setstacksize(pa, size);
}
size_t Platform::get_thread_stack_size(pthread_attr_t* pa) {
size_t mystacksize;
pthread_attr_getstacksize(pa, &mystacksize);
return mystacksize;
}
This paragraph is used only if PLATFORM_POSIX is defined.
The function Platform::create_thread is used in 1/wp (§11).
The function Platform::join_thread is used in 1/wp (§11).
The function Platform::init_thread is used in 1/wp (§11).
The function Platform::get_thread_stack_size is used in 1/wp (§11).
define CREATE_MUTEX(name)
static pthread_mutex_t name = PTHREAD_MUTEX_INITIALIZER;
define LOCK_MUTEX(name) pthread_mutex_lock(&name);
define UNLOCK_MUTEX(name) pthread_mutex_unlock(&name);
This paragraph is used only if PLATFORM_POSIX is defined.