correct way to check arguments to 'strftime'

This commit is contained in:
Roberto Ierusalimschy 2009-08-25 16:58:08 -03:00
parent 4e1ffc482a
commit f096ab5421
2 changed files with 41 additions and 23 deletions

View File

@ -1,5 +1,5 @@
/*
** $Id: loslib.c,v 1.23 2008/01/18 15:37:10 roberto Exp roberto $
** $Id: loslib.c,v 1.24 2008/06/13 16:59:00 roberto Exp roberto $
** Standard Operating System library
** See Copyright Notice in lua.h
*/
@ -121,6 +121,30 @@ static int getfield (lua_State *L, const char *key, int d) {
}
static const char *checkoption (lua_State *L, const char *conv, char *buff) {
static const char *const options[] = { LUA_STRFTIMEOPTIONS };
unsigned int i;
for (i = 0; i < sizeof(options)/sizeof(options[0]); i += 2) {
if (*conv != '\0' && strchr(options[i], *conv) != NULL) {
buff[1] = *conv;
if (*options[i + 1] == '\0') { /* one-char conversion specifier? */
buff[2] = '\0'; /* end buffer */
return conv + 1;
}
else if (*(conv + 1) != '\0' &&
strchr(options[i + 1], *(conv + 1)) != NULL) {
buff[2] = *(conv + 1); /* valid two-char conversion specifier */
buff[3] = '\0'; /* end buffer */
return conv + 2;
}
}
}
luaL_argerror(L, 1,
lua_pushfstring(L, "invalid conversion specifier '%%%s'", conv));
return conv; /* to avoid warnings */
}
static int os_date (lua_State *L) {
const char *s = luaL_optstring(L, 1, "%c");
time_t t = luaL_opt(L, (time_t)luaL_checknumber, 2, time(NULL));
@ -146,27 +170,17 @@ static int os_date (lua_State *L) {
setboolfield(L, "isdst", stm->tm_isdst);
}
else {
char cc[3];
char cc[4];
luaL_Buffer b;
cc[0] = '%';
luaL_buffinit(L, &b);
for (; *s; s++) {
while (*s) {
if (*s != '%') /* no conversion specifier? */
luaL_addchar(&b, *s);
luaL_addchar(&b, *s++);
else {
size_t reslen;
int i = 1;
char buff[200]; /* should be big enough for any conversion result */
if (*(++s) != '\0' && strchr(LUA_STRFTIMEPREFIX, *s))
cc[i++] = *(s++);
if (*s != '\0' && strchr(LUA_STRFTIMEOPTIONS, *s))
cc[i++] = *s;
else {
const char *msg = lua_pushfstring(L,
"invalid conversion specifier '%%%c'", *s);
return luaL_argerror(L, 1, msg);
}
cc[i] = '\0';
s = checkoption(L, s + 1, cc);
reslen = strftime(buff, sizeof(buff), cc, stm);
luaL_addlstring(&b, buff, reslen);
}

View File

@ -1,5 +1,5 @@
/*
** $Id: luaconf.h,v 1.107 2009/07/15 17:26:14 roberto Exp roberto $
** $Id: luaconf.h,v 1.108 2009/07/15 17:57:30 roberto Exp roberto $
** Configuration file for Lua
** See Copyright Notice in lua.h
*/
@ -667,14 +667,18 @@ union luai_Cast { double l_d; long l_l; };
/*
@@ LUA_STRFTIMEOPTIONS is the list of valid conversion specifier
@* characters for the 'strftime' function;
@@ LUA_STRFTIMEPREFIX is the list of valid modifiers for
@* that function.
** CHANGE them if you want to use non-ansi options specific to your system.
@@ LUA_STRFTIMEOPTIONS is the list of valid conversion specifiers
@* for the 'strftime' function;
** CHANGE it if you want to use non-ansi options specific to your system.
*/
#define LUA_STRFTIMEOPTIONS "aAbBcdHIjmMpSUwWxXyYz%"
#define LUA_STRFTIMEPREFIX ""
#if !defined(LUA_USE_POSIX)
#define LUA_STRFTIMEOPTIONS "aAbBcdHIjmMpSUwWxXyYz%", ""
#else
#define LUA_STRFTIMEOPTIONS "aAbBcCdDeFgGhHIjmMnprRStTuUVwWxXyYzZ%", "", \
"E", "cCxXyY", \
"O", "deHImMSuUVwWy"
#endif