commit 86add535d8ee1936c8ff2e9e74e8024377e7b296
parent d987cf1f812b131788029d6de0c81ed64020e522
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 6 Jun 2005 10:30:30 -0300
'popen' is back
Diffstat:
M | liolib.c | | | 99 | +++++++++++++++++++++++++++++++++++++++++++++++++++++--------------------------- |
1 file changed, 66 insertions(+), 33 deletions(-)
diff --git a/liolib.c b/liolib.c
@@ -1,5 +1,5 @@
/*
-** $Id: liolib.c,v 2.60 2005/05/16 21:19:00 roberto Exp roberto $
+** $Id: liolib.c,v 2.61 2005/05/25 13:21:26 roberto Exp roberto $
** Standard I/O (and system) library
** See Copyright Notice in lua.h
*/
@@ -20,8 +20,8 @@
-#define IO_INPUT 1
-#define IO_OUTPUT 2
+#define IO_INPUT 1
+#define IO_OUTPUT 2
static const char *const fnames[] = {"input", "output"};
@@ -91,29 +91,45 @@ static FILE **newfile (lua_State *L) {
}
+/*
+** this function has a separated environment, which defines the
+** correct __close for 'popen' files
+*/
+static int io_pclose (lua_State *L) {
+ FILE **p = topfile(L);
+ int ok = lua_pclose(L, *p);
+ if (ok) *p = NULL;
+ return pushresult(L, ok, NULL);
+}
+
+
+static int io_fclose (lua_State *L) {
+ FILE **p = topfile(L);
+ int ok = (fclose(*p) == 0);
+ if (ok) *p = NULL;
+ return pushresult(L, ok, NULL);
+}
+
+
static int aux_close (lua_State *L) {
- FILE *f = tofile(L);
- if (f == stdin || f == stdout || f == stderr)
- return 0; /* file cannot be closed */
- else {
- int ok = (fclose(f) == 0);
- if (ok)
- *(FILE **)lua_touserdata(L, 1) = NULL; /* mark file as closed */
- return ok;
- }
+ lua_getfenv(L, 1);
+ lua_getfield(L, -1, "__close");
+ return (lua_tocfunction(L, -1))(L);
}
static int io_close (lua_State *L) {
if (lua_isnone(L, 1))
lua_rawgeti(L, LUA_ENVIRONINDEX, IO_OUTPUT);
- return pushresult(L, aux_close(L), NULL);
+ tofile(L); /* make sure argument is a file */
+ return aux_close(L);
}
static int io_gc (lua_State *L) {
- FILE **f = topfile(L);
- if (*f != NULL) /* ignore closed files */
+ FILE *f = *topfile(L);
+ /* ignore closed files and standard files */
+ if (f != NULL && f != stdin && f != stdout && f != stderr)
aux_close(L);
return 0;
}
@@ -138,6 +154,15 @@ static int io_open (lua_State *L) {
}
+static int io_popen (lua_State *L) {
+ const char *filename = luaL_checkstring(L, 1);
+ const char *mode = luaL_optstring(L, 2, "r");
+ FILE **pf = newfile(L);
+ *pf = lua_popen(L, filename, mode);
+ return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
+}
+
+
static int io_tmpfile (lua_State *L) {
FILE **pf = newfile(L);
*pf = tmpfile();
@@ -352,7 +377,7 @@ static int io_readline (lua_State *L) {
luaL_error(L, "file is already closed");
sucess = read_line(L, f);
if (ferror(f))
- luaL_error(L, "%s", strerror(errno));
+ return luaL_error(L, "%s", strerror(errno));
if (sucess) return 1;
else { /* EOF */
if (lua_toboolean(L, lua_upvalueindex(2))) { /* generator created file? */
@@ -439,6 +464,7 @@ static const luaL_reg iolib[] = {
{"close", io_close},
{"flush", io_flush},
{"open", io_open},
+ {"popen", io_popen},
{"read", io_read},
{"tmpfile", io_tmpfile},
{"type", io_type},
@@ -469,30 +495,37 @@ static void createmeta (lua_State *L) {
}
-static void createupval (lua_State *L) {
- lua_newtable(L);
- /* create (and set) default files */
- *newfile(L) = stdin;
- lua_rawseti(L, -2, IO_INPUT);
- *newfile(L) = stdout;
- lua_rawseti(L, -2, IO_OUTPUT);
+static void createstdfile (lua_State *L, FILE *f, int k, const char *fname) {
+ *newfile(L) = f;
+ if (k > 0) {
+ lua_pushvalue(L, -1);
+ lua_rawseti(L, LUA_ENVIRONINDEX, k);
+ }
+ lua_setfield(L, -2, fname);
}
-
LUALIB_API int luaopen_io (lua_State *L) {
createmeta(L);
- createupval(L);
- lua_pushvalue(L, -1);
+ /* create new (private) environment */
+ lua_newtable(L);
lua_replace(L, LUA_ENVIRONINDEX);
+ /* open library */
luaL_openlib(L, LUA_IOLIBNAME, iolib, 0);
- /* put predefined file handles into `io' table */
- lua_rawgeti(L, -2, IO_INPUT); /* get current input from upval */
- lua_setfield(L, -2, "stdin"); /* io.stdin = upval[IO_INPUT] */
- lua_rawgeti(L, -2, IO_OUTPUT); /* get current output from upval */
- lua_setfield(L, -2, "stdout"); /* io.stdout = upval[IO_OUTPUT] */
- *newfile(L) = stderr;
- lua_setfield(L, -2, "stderr"); /* io.stderr = newfile(stderr) */
+ /* create (and set) default files */
+ createstdfile(L, stdin, IO_INPUT, "stdin");
+ createstdfile(L, stdout, IO_OUTPUT, "stdout");
+ createstdfile(L, stderr, 0, "stderr");
+ /* create environment for 'popen' */
+ lua_getfield(L, -1, "popen");
+ lua_newtable(L);
+ lua_pushcfunction(L, io_pclose);
+ lua_setfield(L, -2, "__close");
+ lua_setfenv(L, -2);
+ lua_pop(L, 1); /* pop 'popen' */
+ /* set default close function */
+ lua_pushcfunction(L, io_fclose);
+ lua_setfield(L, LUA_ENVIRONINDEX, "__close");
return 1;
}