commit f6bc7884be000a82809c8f973a81b2ea50760937
parent 32a5d96dfc846ccfe63e6272d385fe963e025b61
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 17 Sep 2002 17:35:32 -0300
new generators for reading a file line by line
Diffstat:
M | liolib.c | | | 90 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------- |
1 file changed, 69 insertions(+), 21 deletions(-)
diff --git a/liolib.c b/liolib.c
@@ -1,5 +1,5 @@
/*
-** $Id: liolib.c,v 2.16 2002/08/16 20:02:13 roberto Exp roberto $
+** $Id: liolib.c,v 2.17 2002/08/21 14:57:48 roberto Exp roberto $
** Standard I/O (and system) library
** See Copyright Notice in lua.h
*/
@@ -32,7 +32,6 @@
#define FILEHANDLE "FileHandle"
-#define CLOSEDFILEHANDLE "ClosedFileHandle"
#define IO_INPUT "_input"
#define IO_OUTPUT "_output"
@@ -54,13 +53,17 @@ static int pushresult (lua_State *L, int i) {
static FILE *tofile (lua_State *L, int findex) {
FILE **f = (FILE **)lua_touserdata(L, findex);
- if (f && lua_getmetatable(L, findex) &&
+ if (f && *f && lua_getmetatable(L, findex) &&
lua_rawequal(L, -1, lua_upvalueindex(1))) {
lua_pop(L, 1);
return *f;
}
- if (findex > 0)
- luaL_argerror(L, findex, "bad file");
+ if (findex > 0) {
+ if (f && *f == NULL)
+ luaL_error(L, "attempt to use a closed file");
+ else
+ luaL_argerror(L, findex, "bad file");
+ }
return NULL;
}
@@ -96,22 +99,29 @@ static int setnewfile (lua_State *L, FILE *f) {
}
+static int aux_close (lua_State *L) {
+ FILE *f = tofile(L, 1);
+ if (f == stdin || f == stdout || f == stderr)
+ return 0; /* file cannot be closed */
+ *(FILE **)lua_touserdata(L, 1) = NULL; /* mark file as closed */
+ return (pclose(f) != -1) || (fclose(f) == 0);
+}
+
+
static int io_close (lua_State *L) {
- FILE *f;
- int status = 1;
if (lua_isnone(L, 1)) {
lua_pushstring(L, IO_OUTPUT);
lua_rawget(L, lua_upvalueindex(1));
}
- f = tofile(L, 1);
- if (f != stdin && f != stdout && f != stderr) {
- lua_settop(L, 1); /* make sure file is on top */
- lua_pushliteral(L, CLOSEDFILEHANDLE);
- lua_rawget(L, LUA_REGISTRYINDEX);
- lua_setmetatable(L, 1);
- status = (pclose(f) != -1) || (fclose(f) == 0);
- }
- return pushresult(L, status);
+ return pushresult(L, aux_close(L));
+}
+
+
+static int io_gc (lua_State *L) {
+ FILE **f = (FILE **)lua_touserdata(L, 1);
+ if (!(f && *f == NULL)) /* ignore closed files */
+ aux_close(L);
+ return 0;
}
@@ -182,6 +192,30 @@ static int io_output (lua_State *L) {
}
+static int io_readline (lua_State *L);
+
+static int io_lines (lua_State *L) {
+ FILE *f = fopen(luaL_check_string(L, 1), "r");
+ luaL_arg_check(L, f, 1, strerror(errno));
+ lua_pushliteral(L, FILEHANDLE);
+ lua_rawget(L, LUA_REGISTRYINDEX);
+ newfile(L, f);
+ lua_pushboolean(L, 1); /* must close file when finished */
+ lua_pushcclosure(L, io_readline, 3);
+ return 1;
+}
+
+static int f_lines (lua_State *L) {
+ tofile(L, 1); /* check that it's a valid file handle */
+ lua_pushliteral(L, FILEHANDLE);
+ lua_rawget(L, LUA_REGISTRYINDEX);
+ lua_pushvalue(L, 1);
+ lua_pushboolean(L, 0); /* does not close file when finished */
+ lua_pushcclosure(L, io_readline, 3);
+ return 1;
+}
+
+
/*
** {======================================================
** READ
@@ -303,6 +337,22 @@ static int f_read (lua_State *L) {
return g_read(L, tofile(L, 1), 2);
}
+
+static int io_readline (lua_State *L) {
+ FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(2));
+ if (f == NULL) /* file is already closed? */
+ luaL_error(L, "file is already closed");
+ if (read_line(L, f)) return 1;
+ else { /* EOF */
+ if (lua_toboolean(L, lua_upvalueindex(3))) { /* generator created file? */
+ lua_settop(L, 0);
+ lua_pushvalue(L, lua_upvalueindex(2));
+ aux_close(L); /* close it */
+ }
+ return 0;
+ }
+}
+
/* }====================================================== */
@@ -366,6 +416,7 @@ static int f_flush (lua_State *L) {
static const luaL_reg iolib[] = {
{"input", io_input},
{"output", io_output},
+ {"lines", io_lines},
{"close", io_close},
{"flush", io_flush},
{"open", io_open},
@@ -380,6 +431,7 @@ static const luaL_reg iolib[] = {
static const luaL_reg flib[] = {
{"flush", f_flush},
{"read", f_read},
+ {"lines", f_lines},
{"seek", f_seek},
{"write", f_write},
{"close", io_close},
@@ -393,7 +445,7 @@ static void createmeta (lua_State *L) {
/* close files when collected */
lua_pushliteral(L, "__gc"); /* S: `gc' mt FH */
lua_pushvalue(L, -2); /* S: mt `gc' mt FH */
- lua_pushcclosure(L, io_close, 1); /* S: close `gc' mt FH */
+ lua_pushcclosure(L, io_gc, 1); /* S: close `gc' mt FH */
lua_rawset(L, -3); /* S: mt FH */
/* file methods */
lua_pushliteral(L, "__gettable"); /* S: `gettable' mt FH */
@@ -403,10 +455,6 @@ static void createmeta (lua_State *L) {
luaL_openlib(L, flib, 1); /* S: mt FH */
/* put new metatable into registry */
lua_rawset(L, LUA_REGISTRYINDEX); /* S: empty */
- /* meta table for CLOSEDFILEHANDLE */
- lua_pushliteral(L, CLOSEDFILEHANDLE);
- lua_newtable(L);
- lua_rawset(L, LUA_REGISTRYINDEX);
}
/* }====================================================== */