#include <windows.h>

#include <shlobj.h>

#include <stdio.h>

#include <tchar.h>

#define BUFSIZE 256

#define MSGSIZE 1024

#define SKIP_PREFIX

#define SEARCH_PATH

#define RC_NO_STD_HANDLES 100

#define RC_CREATE_PROCESS 101

#define RC_BAD_VIRTUAL_PATH 102

#define RC_NO_PYTHON 103

#define RC_NO_MEMORY 104

#if defined(SCRIPT_WRAPPER)

#define RC_NO_SCRIPT 105

#if defined(VENV_REDIRECT)

#define RC_NO_VENV_CFG 106

#define RC_BAD_VENV_CFG 107

static FILE * log_fp = NULL;

static wchar_t *

skip_whitespace(wchar_t * p)

{

while (*p && isspace(*p))

++p;

return p;

}

static void

debug(wchar_t * format, ...)

{

va_list va;

if (log_fp != NULL) {

va_start(va, format);

vfwprintf_s(log_fp, format, va);

va_end(va);

}

}

static void

winerror(int rc, wchar_t * message, int size)

{

FormatMessageW(

FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,

NULL, rc, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),

message, size, NULL);

}

static void

error(int rc, wchar_t * format, ... )

{

va_list va;

wchar_t message[MSGSIZE];

wchar_t win_message[MSGSIZE];

int len;

va_start(va, format);

len = _vsnwprintf_s(message, MSGSIZE, _TRUNCATE, format, va);

va_end(va);

if (rc == 0) { /* a Windows error */

winerror(GetLastError(), win_message, MSGSIZE);

if (len >= 0) {

_snwprintf_s(&message[len], MSGSIZE - len, _TRUNCATE, L": %ls",

win_message);

}

}

#if !defined(_WINDOWS)

fwprintf(stderr, L"%ls\n", message);

MessageBoxW(NULL, message, L"Python Launcher is sorry to say ...",

MB_OK);

exit(rc);

}

static wchar_t * get_env(wchar_t * key)

{

/* This is not thread-safe, just like getenv */

static wchar_t buf[BUFSIZE];

DWORD result = GetEnvironmentVariableW(key, buf, BUFSIZE);

if (result >= BUFSIZE) {

/* Large environment variable. Accept some leakage */

wchar_t *buf2 = (wchar_t*)malloc(sizeof(wchar_t) * (result+1));

if (buf2 == NULL) {

error(RC_NO_MEMORY, L"Could not allocate environment buffer");

}

GetEnvironmentVariableW(key, buf2, result);

return buf2;

}

if (result == 0)

/* Either some error, e.g. ERROR_ENVVAR_NOT_FOUND,

return NULL;

return buf;

}

#if defined(_DEBUG)

#if defined(_WINDOWS)

#define PYTHON_EXECUTABLE L"pythonw_d.exe"

#define PYTHON_EXECUTABLE L"python_d.exe"

#if defined(_WINDOWS)

#define PYTHON_EXECUTABLE L"pythonw.exe"

#define EXECUTABLEPATH_VALUE L"WindowedExecutablePath"

#define PYTHON_EXECUTABLE L"python.exe"

#define EXECUTABLEPATH_VALUE L"ExecutablePath"

#define MAX_VERSION_SIZE 8

typedef struct {

wchar_t version[MAX_VERSION_SIZE]; /* m.n */

int bits; /* 32 or 64 */

wchar_t executable[MAX_PATH];

wchar_t exe_display[MAX_PATH];

} INSTALLED_PYTHON;

#define MAX_INSTALLED_PYTHONS 100

static INSTALLED_PYTHON installed_pythons[MAX_INSTALLED_PYTHONS];

static size_t num_installed_pythons = 0;

#define IP_BASE_SIZE 80

#define IP_VERSION_SIZE 8

#define IP_SIZE (IP_BASE_SIZE + IP_VERSION_SIZE)

#define CORE_PATH L"SOFTWARE\\Python\\PythonCore"

#define LOOKASIDE_PATH L"SOFTWARE\\Microsoft\\AppModel\\Lookaside\\user\\Software\\Python\\PythonCore"

static wchar_t * location_checks[] = {

L"\\",

L"\\PCbuild\\win32\\",

L"\\PCbuild\\amd64\\",

/* To support early 32bit versions of Python that stuck the build binaries

L"\\PCbuild\\",

NULL

};

static INSTALLED_PYTHON *

find_existing_python(const wchar_t * path)

{

INSTALLED_PYTHON * result = NULL;

size_t i;

INSTALLED_PYTHON * ip;

for (i = 0, ip = installed_pythons; i < num_installed_pythons; i++, ip++) {

if (_wcsicmp(path, ip->executable) == 0) {

result = ip;

break;

}

}

return result;

}

static INSTALLED_PYTHON *

find_existing_python2(int bits, const wchar_t * version)

{

INSTALLED_PYTHON * result = NULL;

size_t i;

INSTALLED_PYTHON * ip;

for (i = 0, ip = installed_pythons; i < num_installed_pythons; i++, ip++) {

if (bits == ip->bits && _wcsicmp(version, ip->version) == 0) {

result = ip;

break;

}

}

return result;

}

static void

_locate_pythons_for_key(HKEY root, LPCWSTR subkey, REGSAM flags, int bits,

int display_name_only)

{

HKEY core_root, ip_key;

LSTATUS status = RegOpenKeyExW(root, subkey, 0, flags, &core_root);

wchar_t message[MSGSIZE];

DWORD i;

size_t n;

BOOL ok, append_name;

DWORD type, data_size, attrs;

INSTALLED_PYTHON * ip, * pip;

wchar_t ip_version[IP_VERSION_SIZE];

wchar_t ip_path[IP_SIZE];

wchar_t * check;

wchar_t ** checkp;

wchar_t *key_name = (root == HKEY_LOCAL_MACHINE) ? L"HKLM" : L"HKCU";

if (status != ERROR_SUCCESS)

debug(L"locate_pythons_for_key: unable to open PythonCore key in %ls\n",

key_name);

else {

ip = &installed_pythons[num_installed_pythons];

for (i = 0; num_installed_pythons < MAX_INSTALLED_PYTHONS; i++) {

status = RegEnumKeyW(core_root, i, ip_version, IP_VERSION_SIZE);

if (status != ERROR_SUCCESS) {

if (status != ERROR_NO_MORE_ITEMS) {

/* unexpected error */

winerror(status, message, MSGSIZE);

debug(L"Can't enumerate registry key for version %ls: %ls\n",

ip_version, message);

}

break;

}

else {

wcsncpy_s(ip->version, MAX_VERSION_SIZE, ip_version,

MAX_VERSION_SIZE-1);

/* Still treating version as "x.y" rather than sys.winver

check = wcsrchr(ip->version, L'-');

if (check && !wcscmp(check, L"-32")) {

*check = L'\0';

}

_snwprintf_s(ip_path, IP_SIZE, _TRUNCATE,

L"%ls\\%ls\\InstallPath", subkey, ip_version);

status = RegOpenKeyExW(root, ip_path, 0, flags, &ip_key);

if (status != ERROR_SUCCESS) {

winerror(status, message, MSGSIZE);

/* Note: 'message' already has a trailing \n*/

debug(L"%ls\\%ls: %ls", key_name, ip_path, message);

continue;

}

data_size = sizeof(ip->executable) - 1;

append_name = FALSE;

#ifdef EXECUTABLEPATH_VALUE

status = RegQueryValueExW(ip_key, EXECUTABLEPATH_VALUE, NULL, &type,

(LPBYTE)ip->executable, &data_size);

status = ERROR_FILE_NOT_FOUND; /* actual error doesn't matter */

if (status != ERROR_SUCCESS || type != REG_SZ || !data_size) {

append_name = TRUE;

data_size = sizeof(ip->executable) - 1;

status = RegQueryValueExW(ip_key, NULL, NULL, &type,

(LPBYTE)ip->executable, &data_size);

if (status != ERROR_SUCCESS) {

winerror(status, message, MSGSIZE);

debug(L"%ls\\%ls: %ls\n", key_name, ip_path, message);

RegCloseKey(ip_key);

continue;

}

}

RegCloseKey(ip_key);

if (type != REG_SZ) {

continue;

}

data_size = data_size / sizeof(wchar_t) - 1; /* for NUL */

if (ip->executable[data_size - 1] == L'\\')

--data_size; /* reg value ended in a backslash */

/* ip->executable is data_size long */

for (checkp = location_checks; *checkp; ++checkp) {

check = *checkp;

if (append_name) {

_snwprintf_s(&ip->executable[data_size],

MAX_PATH - data_size,

MAX_PATH - data_size,

L"%ls%ls", check, PYTHON_EXECUTABLE);

}

attrs = GetFileAttributesW(ip->executable);

if (attrs == INVALID_FILE_ATTRIBUTES) {

winerror(GetLastError(), message, MSGSIZE);

debug(L"locate_pythons_for_key: %ls: %ls",

ip->executable, message);

}

else if (attrs & FILE_ATTRIBUTE_DIRECTORY) {

debug(L"locate_pythons_for_key: '%ls' is a directory\n",

ip->executable);

}

else if (find_existing_python(ip->executable)) {

debug(L"locate_pythons_for_key: %ls: already found\n",

ip->executable);

}

else {

/* check the executable type. */

if (bits) {

ip->bits = bits;

} else {

ok = GetBinaryTypeW(ip->executable, &attrs);

if (!ok) {

debug(L"Failure getting binary type: %ls\n",

ip->executable);

}

else {

if (attrs == SCS_64BIT_BINARY)

ip->bits = 64;

else if (attrs == SCS_32BIT_BINARY)

ip->bits = 32;

else

ip->bits = 0;

}

}

if (ip->bits == 0) {

debug(L"locate_pythons_for_key: %ls: \

invalid binary type: %X\n",

ip->executable, attrs);

}

else {

if (display_name_only) {

/* display just the executable name. This is

const wchar_t *name = wcsrchr(ip->executable, L'\\');

if (name) {

wcscpy_s(ip->exe_display, MAX_PATH, name+1);

}

}

if (wcschr(ip->executable, L' ') != NULL) {

/* has spaces, so quote, and set original as

if (!ip->exe_display[0]) {

wcscpy_s(ip->exe_display, MAX_PATH, ip->executable);

}

n = wcslen(ip->executable);

memmove(&ip->executable[1],

ip->executable, n * sizeof(wchar_t));

ip->executable[0] = L'\"';

ip->executable[n + 1] = L'\"';

ip->executable[n + 2] = L'\0';

}

debug(L"locate_pythons_for_key: %ls \

is a %dbit executable\n",

ip->executable, ip->bits);

if (find_existing_python2(ip->bits, ip->version)) {

debug(L"locate_pythons_for_key: %ls-%i: already \

found\n", ip->version, ip->bits);

}

else {

++num_installed_pythons;

pip = ip++;

if (num_installed_pythons >=

MAX_INSTALLED_PYTHONS)

break;

}

}

}

}

}

}

RegCloseKey(core_root);

}

}

static int

compare_pythons(const void * p1, const void * p2)

{

INSTALLED_PYTHON * ip1 = (INSTALLED_PYTHON *) p1;

INSTALLED_PYTHON * ip2 = (INSTALLED_PYTHON *) p2;

/* note reverse sorting on version */

int result = wcscmp(ip2->version, ip1->version);

if (result == 0)

result = ip2->bits - ip1->bits; /* 64 before 32 */

return result;

}

static void

locate_pythons_for_key(HKEY root, REGSAM flags)

{

_locate_pythons_for_key(root, CORE_PATH, flags, 0, FALSE);

}

static void

locate_store_pythons()

{

#if defined(_M_X64)

/* 64bit process, so look in native registry */

_locate_pythons_for_key(HKEY_LOCAL_MACHINE, LOOKASIDE_PATH,

KEY_READ, 64, TRUE);

/* 32bit process, so check that we're on 64bit OS */

BOOL f64 = FALSE;

if (IsWow64Process(GetCurrentProcess(), &f64) && f64) {

_locate_pythons_for_key(HKEY_LOCAL_MACHINE, LOOKASIDE_PATH,

KEY_READ | KEY_WOW64_64KEY, 64, TRUE);

}

}

static void

locate_venv_python()

{

static wchar_t venv_python[MAX_PATH];

INSTALLED_PYTHON * ip;

wchar_t *virtual_env = get_env(L"VIRTUAL_ENV");

DWORD attrs;

/* Check for VIRTUAL_ENV environment variable */

if (virtual_env == NULL || virtual_env[0] == L'\0') {

return;

}

/* Check for a python executable in the venv */

debug(L"Checking for Python executable in virtual env '%ls'\n", virtual_env);

_snwprintf_s(venv_python, MAX_PATH, _TRUNCATE,

L"%ls\\Scripts\\%ls", virtual_env, PYTHON_EXECUTABLE);

attrs = GetFileAttributesW(venv_python);

if (attrs == INVALID_FILE_ATTRIBUTES) {

debug(L"Python executable %ls missing from virtual env\n", venv_python);

return;

}

ip = &installed_pythons[num_installed_pythons++];

wcscpy_s(ip->executable, MAX_PATH, venv_python);

ip->bits = 0;

wcscpy_s(ip->version, MAX_VERSION_SIZE, L"venv");

}

static void

locate_all_pythons()

{

/* venv Python is highest priority */

locate_venv_python();

#if defined(_M_X64)

/* If we are a 64bit process, first hit the 32bit keys. */

debug(L"locating Pythons in 32bit registry\n");

locate_pythons_for_key(HKEY_CURRENT_USER, KEY_READ | KEY_WOW64_32KEY);

locate_pythons_for_key(HKEY_LOCAL_MACHINE, KEY_READ | KEY_WOW64_32KEY);

/* If we are a 32bit process on a 64bit Windows, first hit the 64bit keys.*/

BOOL f64 = FALSE;

if (IsWow64Process(GetCurrentProcess(), &f64) && f64) {

debug(L"locating Pythons in 64bit registry\n");

locate_pythons_for_key(HKEY_CURRENT_USER, KEY_READ | KEY_WOW64_64KEY);

locate_pythons_for_key(HKEY_LOCAL_MACHINE, KEY_READ | KEY_WOW64_64KEY);

}

/* now hit the "native" key for this process bittedness. */

debug(L"locating Pythons in native registry\n");

locate_pythons_for_key(HKEY_CURRENT_USER, KEY_READ);

locate_pythons_for_key(HKEY_LOCAL_MACHINE, KEY_READ);

/* Store-installed Python is lowest priority */

locate_store_pythons();

qsort(installed_pythons, num_installed_pythons, sizeof(INSTALLED_PYTHON),

compare_pythons);

}

static INSTALLED_PYTHON *

find_python_by_version(wchar_t const * wanted_ver)

{

INSTALLED_PYTHON * result = NULL;

INSTALLED_PYTHON * ip = installed_pythons;

size_t i, n;

size_t wlen = wcslen(wanted_ver);

int bits = 0;

if (wcsstr(wanted_ver, L"-32")) {

bits = 32;

wlen -= wcslen(L"-32");

}

else if (wcsstr(wanted_ver, L"-64")) { /* Added option to select 64 bit explicitly */

bits = 64;

wlen -= wcslen(L"-64");

}

for (i = 0; i < num_installed_pythons; i++, ip++) {

n = wcslen(ip->version);

if (n > wlen)

n = wlen;

if ((wcsncmp(ip->version, wanted_ver, n) == 0) &&

/* bits == 0 => don't care */

((bits == 0) || (ip->bits == bits))) {

result = ip;

break;

}

}

return result;

}

static wchar_t appdata_ini_path[MAX_PATH];

static wchar_t launcher_ini_path[MAX_PATH];

static wchar_t *

get_configured_value(wchar_t * key)

{

static wchar_t configured_value[MSGSIZE];

wchar_t * result = NULL;

wchar_t * found_in = L"environment";

DWORD size;

/* First, search the environment. */

_snwprintf_s(configured_value, MSGSIZE, _TRUNCATE, L"py_%ls", key);

result = get_env(configured_value);

if (result == NULL && appdata_ini_path[0]) {

/* Not in environment: check local configuration. */

size = GetPrivateProfileStringW(L"defaults", key, NULL,

configured_value, MSGSIZE,

appdata_ini_path);

if (size > 0) {

result = configured_value;

found_in = appdata_ini_path;

}

}

if (result == NULL && launcher_ini_path[0]) {

/* Not in environment or local: check global configuration. */

size = GetPrivateProfileStringW(L"defaults", key, NULL,

configured_value, MSGSIZE,

launcher_ini_path);

if (size > 0) {

result = configured_value;

found_in = launcher_ini_path;

}

}

if (result) {

debug(L"found configured value '%ls=%ls' in %ls\n",

key, result, found_in ? found_in : L"(unknown)");

} else {

debug(L"found no configured value for '%ls'\n", key);

}

return result;

}

static INSTALLED_PYTHON *

locate_python(wchar_t * wanted_ver, BOOL from_shebang)

{

static wchar_t config_key [] = { L"pythonX" };

static wchar_t * last_char = &config_key[sizeof(config_key) /

sizeof(wchar_t) - 2];

INSTALLED_PYTHON * result = NULL;

size_t n = wcslen(wanted_ver);

wchar_t * configured_value;

if (num_installed_pythons == 0)

locate_all_pythons();

if (n == 1) { /* just major version specified */

*last_char = *wanted_ver;

configured_value = get_configured_value(config_key);

if (configured_value != NULL)

wanted_ver = configured_value;

}

if (*wanted_ver) {

result = find_python_by_version(wanted_ver);

debug(L"search for Python version '%ls' found ", wanted_ver);

if (result) {

debug(L"'%ls'\n", result->executable);

} else {

debug(L"no interpreter\n");

}

}

else {

*last_char = L'\0'; /* look for an overall default */

result = find_python_by_version(L"venv");

if (result == NULL) {

configured_value = get_configured_value(config_key);

if (configured_value)

result = find_python_by_version(configured_value);

}

/* Not found a value yet - try by major version.

if (result == NULL)

result = find_python_by_version(from_shebang ? L"2" : L"3");

if (result == NULL)

result = find_python_by_version(from_shebang ? L"3" : L"2");

debug(L"search for default Python found ");

if (result) {

debug(L"version %ls at '%ls'\n",

result->version, result->executable);

} else {

debug(L"no interpreter\n");

}

}

return result;

}

#if defined(SCRIPT_WRAPPER)

#if defined(_WINDOWS)

#define SCRIPT_SUFFIX L"-script.pyw"

#define SCRIPT_SUFFIX L"-script.py"

static wchar_t wrapped_script_path[MAX_PATH];

static void

locate_wrapped_script()

{

wchar_t * p;

size_t plen;

DWORD attrs;

plen = GetModuleFileNameW(NULL, wrapped_script_path, MAX_PATH);

p = wcsrchr(wrapped_script_path, L'.');

if (p == NULL) {

debug(L"GetModuleFileNameW returned value has no extension: %ls\n",

wrapped_script_path);

error(RC_NO_SCRIPT, L"Wrapper name '%ls' is not valid.", wrapped_script_path);

}

wcsncpy_s(p, MAX_PATH - (p - wrapped_script_path) + 1, SCRIPT_SUFFIX, _TRUNCATE);

attrs = GetFileAttributesW(wrapped_script_path);

if (attrs == INVALID_FILE_ATTRIBUTES) {

debug(L"File '%ls' non-existent\n", wrapped_script_path);

error(RC_NO_SCRIPT, L"Script file '%ls' is not present.", wrapped_script_path);

}

debug(L"Using wrapped script file '%ls'\n", wrapped_script_path);

}

static BOOL

safe_duplicate_handle(HANDLE in, HANDLE * pout)

{

BOOL ok;

HANDLE process = GetCurrentProcess();

DWORD rc;

*pout = NULL;

ok = DuplicateHandle(process, in, process, pout, 0, TRUE,

DUPLICATE_SAME_ACCESS);

if (!ok) {

rc = GetLastError();

if (rc == ERROR_INVALID_HANDLE) {

debug(L"DuplicateHandle returned ERROR_INVALID_HANDLE\n");

ok = TRUE;

}

else {

debug(L"DuplicateHandle returned %d\n", rc);

}

}

return ok;

}

static BOOL WINAPI

ctrl_c_handler(DWORD code)

{

return TRUE; /* We just ignore all control events. */

}

static void

run_child(wchar_t * cmdline)

{

HANDLE job;

JOBOBJECT_EXTENDED_LIMIT_INFORMATION info;

DWORD rc;

BOOL ok;

STARTUPINFOW si;

PROCESS_INFORMATION pi;

#if defined(_WINDOWS)

/*

MSG msg;

PostMessage(0, 0, 0, 0);

GetMessage(&msg, 0, 0, 0);

debug(L"run_child: about to run '%ls'\n", cmdline);

job = CreateJobObject(NULL, NULL);

ok = QueryInformationJobObject(job, JobObjectExtendedLimitInformation,

&info, sizeof(info), &rc);

if (!ok || (rc != sizeof(info)) || !job)

error(RC_CREATE_PROCESS, L"Job information querying failed");

info.BasicLimitInformation.LimitFlags |= JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE |

JOB_OBJECT_LIMIT_SILENT_BREAKAWAY_OK;

ok = SetInformationJobObject(job, JobObjectExtendedLimitInformation, &info,

sizeof(info));

if (!ok)

error(RC_CREATE_PROCESS, L"Job information setting failed");

memset(&si, 0, sizeof(si));

GetStartupInfoW(&si);

ok = safe_duplicate_handle(GetStdHandle(STD_INPUT_HANDLE), &si.hStdInput);

if (!ok)

error(RC_NO_STD_HANDLES, L"stdin duplication failed");

ok = safe_duplicate_handle(GetStdHandle(STD_OUTPUT_HANDLE), &si.hStdOutput);

if (!ok)

error(RC_NO_STD_HANDLES, L"stdout duplication failed");

ok = safe_duplicate_handle(GetStdHandle(STD_ERROR_HANDLE), &si.hStdError);

if (!ok)

error(RC_NO_STD_HANDLES, L"stderr duplication failed");

ok = SetConsoleCtrlHandler(ctrl_c_handler, TRUE);

if (!ok)

error(RC_CREATE_PROCESS, L"control handler setting failed");

si.dwFlags = STARTF_USESTDHANDLES;

ok = CreateProcessW(NULL, cmdline, NULL, NULL, TRUE,

0, NULL, NULL, &si, &pi);

if (!ok)

error(RC_CREATE_PROCESS, L"Unable to create process using '%ls'", cmdline);

AssignProcessToJobObject(job, pi.hProcess);

CloseHandle(pi.hThread);

WaitForSingleObjectEx(pi.hProcess, INFINITE, FALSE);

ok = GetExitCodeProcess(pi.hProcess, &rc);

if (!ok)

error(RC_CREATE_PROCESS, L"Failed to get exit code of process");

debug(L"child process exit code: %d\n", rc);

exit(rc);

}

static void

invoke_child(wchar_t * executable, wchar_t * suffix, wchar_t * cmdline)

{

wchar_t * child_command;

size_t child_command_size;

BOOL no_suffix = (suffix == NULL) || (*suffix == L'\0');

BOOL no_cmdline = (*cmdline == L'\0');

if (no_suffix && no_cmdline)

run_child(executable);

else {

if (no_suffix) {

/* add 2 for space separator + terminating NUL. */

child_command_size = wcslen(executable) + wcslen(cmdline) + 2;

}

else {

/* add 3 for 2 space separators + terminating NUL. */

child_command_size = wcslen(executable) + wcslen(suffix) +

wcslen(cmdline) + 3;

}

child_command = calloc(child_command_size, sizeof(wchar_t));

if (child_command == NULL)

error(RC_CREATE_PROCESS, L"unable to allocate %zd bytes for child command.",

child_command_size);

if (no_suffix)

_snwprintf_s(child_command, child_command_size,

child_command_size - 1, L"%ls %ls",

executable, cmdline);

else

_snwprintf_s(child_command, child_command_size,

child_command_size - 1, L"%ls %ls %ls",

executable, suffix, cmdline);

run_child(child_command);

free(child_command);

}

}

typedef struct {

wchar_t *shebang;

BOOL search;

} SHEBANG;

static SHEBANG builtin_virtual_paths [] = {

{ L"/usr/bin/env python", TRUE },

{ L"/usr/bin/python", FALSE },

{ L"/usr/local/bin/python", FALSE },

{ L"python", FALSE },

{ NULL, FALSE },

};

#define MAX_COMMANDS 100

typedef struct {

wchar_t key[MAX_PATH];

wchar_t value[MSGSIZE];

} COMMAND;

static COMMAND commands[MAX_COMMANDS];

static int num_commands = 0;

#if defined(SKIP_PREFIX)

static wchar_t * builtin_prefixes [] = {

/* These must be in an order that the longest matches should be found,

L"/usr/bin/env ",

L"/usr/bin/",

L"/usr/local/bin/",

NULL

};

static wchar_t * skip_prefix(wchar_t * name)

{

wchar_t ** pp = builtin_prefixes;

wchar_t * result = name;

wchar_t * p;

size_t n;

for (; p = *pp; pp++) {

n = wcslen(p);

if (_wcsnicmp(p, name, n) == 0) {

result += n; /* skip the prefix */

if (p[n - 1] == L' ') /* No empty strings in table, so n > 1 */

result = skip_whitespace(result);

break;

}

}

return result;

}

#if defined(SEARCH_PATH)

static COMMAND path_command;

static COMMAND * find_on_path(wchar_t * name)

{

wchar_t * pathext;

size_t varsize;

wchar_t * context = NULL;

wchar_t * extension;

COMMAND * result = NULL;

DWORD len;

errno_t rc;

wcscpy_s(path_command.key, MAX_PATH, name);

if (wcschr(name, L'.') != NULL) {

/* assume it has an extension. */

len = SearchPathW(NULL, name, NULL, MSGSIZE, path_command.value, NULL);

if (len) {

result = &path_command;

}

}

else {

/* No extension - search using registered extensions. */

rc = _wdupenv_s(&pathext, &varsize, L"PATHEXT");

if (rc == 0) {

extension = wcstok_s(pathext, L";", &context);

while (extension) {

len = SearchPathW(NULL, name, extension, MSGSIZE, path_command.value, NULL);

if (len) {

result = &path_command;

break;

}

extension = wcstok_s(NULL, L";", &context);

}

free(pathext);

}

}

return result;

}

static COMMAND * find_command(wchar_t * name)

{

COMMAND * result = NULL;

COMMAND * cp = commands;

int i;

for (i = 0; i < num_commands; i++, cp++) {

if (_wcsicmp(cp->key, name) == 0) {

result = cp;

break;

}

}

#if defined(SEARCH_PATH)

if (result == NULL)

result = find_on_path(name);

return result;

}

static void

update_command(COMMAND * cp, wchar_t * name, wchar_t * cmdline)

{

wcsncpy_s(cp->key, MAX_PATH, name, _TRUNCATE);

wcsncpy_s(cp->value, MSGSIZE, cmdline, _TRUNCATE);

}

static void

add_command(wchar_t * name, wchar_t * cmdline)

{

if (num_commands >= MAX_COMMANDS) {

debug(L"can't add %ls = '%ls': no room\n", name, cmdline);

}

else {

COMMAND * cp = &commands[num_commands++];

update_command(cp, name, cmdline);

}

}

static void

read_config_file(wchar_t * config_path)

{

wchar_t keynames[MSGSIZE];

wchar_t value[MSGSIZE];

DWORD read;

wchar_t * key;

COMMAND * cp;

wchar_t * cmdp;

read = GetPrivateProfileStringW(L"commands", NULL, NULL, keynames, MSGSIZE,

config_path);

if (read == MSGSIZE - 1) {

debug(L"read_commands: %ls: not enough space for names\n", config_path);

}

key = keynames;

while (*key) {