/*

 * POSIX library for Lua 5.1, 5.2 & 5.3.

 * (c) Gary V. Vaughan <gary@vaughan.pe>, 2013-2015

 * (c) Reuben Thomas <rrt@sc3d.org> 2010-2013

 * (c) Natanael Copa <natanael.copa@gmail.com> 2008-2010

 * Clean up and bug fixes by Leo Razoumov <slonik.az@gmail.com> 2006-10-11

 * Luiz Henrique de Figueiredo <lhf@tecgraf.puc-rio.br> 07 Apr 2006 23:17:49

 * Based on original by Claudio Terra for Lua 3.x.

 * With contributions by Roberto Ierusalimschy.

 * With documentation from Steve Donovan 2012

 */

/***

 Standard Posix Library functions.

@module posix.stdlib

*/

#include <config.h>

#include <fcntl.h>	/* for open(2) */

#include <stdlib.h>

#include "_helpers.c"

/***

Abort the program immediately.

@function abort

@see abort(3)

*/

static int

Pabort(lua_State *L)

{

	checknargs(L, 0);

	abort();

	return 0; /* Avoid a compiler warning (or possibly cause one

		     if the compiler's too clever, sigh). */

}

/***

Get value of environment variable, or _all_ variables.

@function getenv

@see getenv(3)

@string[opt] name if nil, get all

@return value if name given, otherwise a name-indexed table of values.

@usage for a,b in pairs(posix.getenv()) do print(a, b) end

*/

static int

Pgetenv(lua_State *L)

{

	checknargs(L, 1);

	if (lua_isnoneornil(L, 1))

	{

		extern char **environ;

		char **e;

		lua_newtable(L);

		for (e=environ; *e!=NULL; e++)

		{

			char *s=*e;

			char *eq=strchr(s, '=');

			if (eq==NULL)		/* will this ever happen? */

			{

				lua_pushstring(L, s);

				lua_pushboolean(L, 1);

			}

			else

			{

				lua_pushlstring(L, s, eq-s);

				lua_pushstring(L, eq+1);

			}

			lua_settable(L, -3);

		}

	}

	else

		lua_pushstring(L, getenv(optstring(L, 1,

			"lua_isnoneornil prevents this happening")));

	return 1;

}

/***

Grant access to a slave pseudoterminal

@function grantpt

@int fd descriptor returned by openpt

@treturn[1] int `0`, if successful

@return[2] nil

@treturn[2] string error message

@treturn[2] int errnum

@see grantpt(3)

@see openpt

@see ptsname

@see unlockpt

*/

static int

Pgrantpt(lua_State *L)

{

	int fd=checkint(L, 1);

	checknargs(L, 1);

	return pushresult(L, grantpt(fd), "grantpt");

}

/***

Create a unique temporary directory.

@function mkdtemp

@string templ pattern that ends in six 'X' characters

@treturn[1] string path to directory, if successful

@return[2] nil

@treturn[2] string error message

@treturn[2] int errnum

@see mkdtemp(3)

*/

static int

Pmkdtemp(lua_State *L)

{

#if defined LPOSIX_2008_COMPLIANT

	const char *path = luaL_checkstring(L, 1);

	size_t path_len = strlen(path) + 1;

	void *ud;

	lua_Alloc lalloc;

	char *tmppath;

	char *r;

	checknargs(L, 1);

	lalloc = lua_getallocf(L, &ud);

	if ((tmppath = lalloc(ud, NULL, 0, path_len)) == NULL)

		return pusherror(L, "lalloc");

	strcpy(tmppath, path);

	if ((r = mkdtemp(tmppath)))

		lua_pushstring(L, tmppath);

	lalloc(ud, tmppath, path_len, 0);

	return (r == NULL) ? pusherror(L, path) : 1;

#else

	return binding_notimplemented(L, "mkdtemp", "C");

#endif

}

/***

Create a unique temporary file.

@function mkstemp

@string templ pattern that ends in six 'X' characters

@treturn[1] int open file descriptor

@treturn[2] string path to file, if successful

@return[2] nil

@treturn[2] string error message

@treturn[2] int errnum

@see mkstemp(3)

@usage P.mkstemp 'wooXXXXXX'

*/

static int

Pmkstemp(lua_State *L)

{

	const char *path = luaL_checkstring(L, 1);

	size_t path_len = strlen(path) + 1;

	void *ud;

	lua_Alloc lalloc;

	char *tmppath;

	int r;

	checknargs(L, 1);

	lalloc = lua_getallocf(L, &ud);

	if ((tmppath = lalloc(ud, NULL, 0, path_len)) == NULL)

		return pusherror(L, "lalloc");

	strcpy(tmppath, path);

	r = mkstemp(tmppath);

	if (r != -1)

	{

		lua_pushinteger(L, r);

		lua_pushstring(L, tmppath);

	}

	lalloc(ud, tmppath, path_len, 0);

	return (r == -1) ? pusherror(L, path) : 2;

}

/***

Open a pseudoterminal.

@function openpt

@int oflags bitwise OR of zero or more of `O_RDWR` and `O_NOCTTY`

@return[1] file descriptor of pseudoterminal, if successful

@return[2] nil

@treturn[2] string error message

@treturn[2] int errnum

@see posix_openpt(3)

@see grantpt

@see ptsname

@see unlockpt

*/

static int

Popenpt(lua_State *L)

{

	int flags = checkint(L, 1);

	checknargs(L, 1);

	/* The name of the pseudo-device is specified by POSIX */

	return pushresult(L, open("/dev/ptmx", flags), NULL);

}

/***

Get the name of a slave pseudo-terminal

@function ptsname

@int fd descriptor returned by @{openpt}

@return[1] path name of the slave terminal device, if successful

@return[2] nil

@treturn[2] string error message

@treturn[2] int errnum

@see ptsname(3)

@see grantpt

@see unlockpt

*/

static int

Pptsname(lua_State *L)

{

	int fd=checkint(L, 1);

	const char* slave;

	checknargs(L, 1);

	slave = ptsname(fd);

	if (!slave)

		return pusherror(L, "getptsname");

	return pushstringresult(slave);

}

/***

Find canonicalized absolute pathname.

@function realpath

@string path file to act on

@treturn[1] string canonicalized absolute path, if successful

@return[2] nil

@treturn[2] string error messag

@treturn[2] int errnum

@see realpath(3)

*/

static int

Prealpath(lua_State *L)

{

	char *s;

	checknargs(L, 1);

	if ((s = realpath(luaL_checkstring(L, 1), NULL)) == NULL)

		return pusherror(L, "realpath");

	lua_pushstring(L, s);

	free(s);

	return 1;

}

/***

Set an environment variable for this process.

(Child processes will inherit this)

@function setenv

@string name

@string[opt] value (maybe nil, meaning 'unset')

@param[opt] overwrite non-nil prevents overwriting a variable

@treturn[1] int `0`, if successful

@return[2] nil

@treturn[2] string error message

@treturn[2] int errnum

@see setenv(3)

*/

static int

Psetenv(lua_State *L)

{

	const char *name=luaL_checkstring(L, 1);

	const char *value=optstring(L, 2, NULL);

	checknargs(L, 3);

	if (value==NULL)

	{

		unsetenv(name);

		return pushresult(L, 0, NULL);

	}

	else

	{

		int overwrite=lua_isnoneornil(L, 3) || lua_toboolean(L, 3);

		return pushresult(L, setenv(name,value,overwrite), NULL);

	}

}

/***

Unlock a pseudoterminal master/slave pair

@function unlockpt

@int fd descriptor returned by openpt

@treturn[1] int `0`, if successful

@return[2] nil

@treturn[2] string error message

@treturn[2] int errnum

@see unlockpt(3)

@see openpt

@see ptsname

@see grantpt

*/

static int

Punlockpt(lua_State *L)

{

	int fd=checkint(L, 1);

	checknargs(L, 1);

	return pushresult(L, unlockpt(fd), "unlockpt");

}

static const luaL_Reg posix_stdlib_fns[] =

{

	LPOSIX_FUNC( Pabort		),

	LPOSIX_FUNC( Pgetenv		),

	LPOSIX_FUNC( Pgrantpt		),

	LPOSIX_FUNC( Pmkdtemp		),

	LPOSIX_FUNC( Pmkstemp		),

	LPOSIX_FUNC( Popenpt		),

	LPOSIX_FUNC( Pptsname		),

	LPOSIX_FUNC( Prealpath		),

	LPOSIX_FUNC( Psetenv		),

	LPOSIX_FUNC( Punlockpt		),

	{NULL, NULL}

};

LUALIB_API int

luaopen_posix_stdlib(lua_State *L)

{

	luaL_register(L, "posix.stdlib", posix_stdlib_fns);

	lua_pushliteral(L, "posix.stdlib for " LUA_VERSION " / " PACKAGE_STRING);

	lua_setfield(L, -2, "version");

	return 1;

}