fs.fnmatch function

expose the C fnmatch function to Lua scripts.

Author: Christophe Delord

build.lua

@@ -556,6 +556,8 @@ local luax_cflags = F{
         "-Werror=implicit-fallthrough",
         "-Werror=missing-prototypes",
 
+        "-Wno-unused-macros",
+
         case(compiler) {
             zig = {
                 "-Weverything",

doc/fs.md

@@ -51,6 +51,14 @@ returns the list of path names matching a pattern.
 
 *Note*: not implemented on Windows.
 
+``` lua
+fs.fnmatch(pattern, string, [flags])
+```
+
+matches `string` against the `pattern` using the `fnmatch` function.
+Returns `true` if the string matches the pattern, `false` otherwise.
+Optional `flags` parameter can be used to modify the matching behavior.
+
 ``` lua
 fs.remove(name)
 fs.rm(name)
@@ -259,6 +267,18 @@ fs.aR, fs.aW, fs.aX
 
 are the User/Group/Other/All Read/Write/eXecute mask for `fs.chmod`.
 
+``` lua
+fs.FNM_NOESCAPE
+fs.FNM_PATHNAME
+fs.FNM_PERIOD
+fs.FNM_FILE_NAME
+fs.FNM_LEADING_DIR
+fs.FNM_CASEFOLD
+fs.FNM_EXTMATCH
+```
+
+are flags for `fs.fnmatch`.
+
 ## Additional functions (Lua)
 
 ``` lua

libluax/fs/_fs.lua

@@ -189,6 +189,20 @@ function fs.inode(name)
     }
 end
 
+local pattern_cache = {}
+
+function fs.fnmatch(pattern, name)
+    local lua_pattern = pattern_cache[pattern]
+    if not lua_pattern then
+        lua_pattern = pattern
+            : gsub("%.", "%%.")
+            : gsub("%*", ".*")
+        lua_pattern = "^"..lua_pattern.."$"
+        pattern_cache[pattern] = lua_pattern
+    end
+    return name:match(lua_pattern) and true or false
+end
+
 function fs.chmod(name, ...)
     local mode = {...}
     if type(mode[1]) == "string" then

libluax/fs/fs.c

@@ -40,6 +40,8 @@ local fs = require "fs"
 #include <stdint.h>
 #include <windows.h>
 #else
+#define _GNU_SOURCE
+#define _DARWIN_C_SOURCE
 #include <fnmatch.h>
 #include <glob.h>
 #endif
@@ -389,6 +391,24 @@ static int fs_glob(lua_State *L)
 
 #endif
 
+/*@@@
+```lua
+fs.fnmatch(pattern, string, [flags])
+```
+matches `string` against the `pattern` using the `fnmatch` function.
+Returns `true` if the string matches the pattern, `false` otherwise.
+Optional `flags` parameter can be used to modify the matching behavior.
+@@@*/
+
+static int fs_fnmatch(lua_State *L)
+{
+    const char *pattern = luaL_checkstring(L, 1);
+    const char *string = luaL_checkstring(L, 2);
+    const int flags = lua_isnoneornil(L, 3) ? 0 : (int)luaL_checkinteger(L, 3);
+    lua_pushboolean(L, fnmatch(pattern, string, flags) == 0);
+    return 1;
+}
+
 /*@@@
 ```lua
 fs.remove(name)
@@ -1173,6 +1193,7 @@ static const luaL_Reg fslib[] =
     {"dir",         fs_dir},
     {"ls",          fs_ls},
     {"glob",        fs_glob},
+    {"fnmatch",     fs_fnmatch},
     {"remove",      fs_remove},
     {"rm",          fs_remove},
     {"rename",      fs_rename},
@@ -1213,6 +1234,17 @@ fs.oR, fs.oW, fs.oX
 fs.aR, fs.aW, fs.aX
 ```
 are the User/Group/Other/All Read/Write/eXecute mask for `fs.chmod`.
+
+```lua
+fs.FNM_NOESCAPE
+fs.FNM_PATHNAME
+fs.FNM_PERIOD
+fs.FNM_FILE_NAME
+fs.FNM_LEADING_DIR
+fs.FNM_CASEFOLD
+fs.FNM_EXTMATCH
+```
+are flags for `fs.fnmatch`.
 @@@*/
 
 LUAMOD_API int luaopen_fs(lua_State *L)
@@ -1238,5 +1270,27 @@ LUAMOD_API int luaopen_fs(lua_State *L)
     set_integer(L, "oR", S_IROTH);
     set_integer(L, "oW", S_IWOTH);
     set_integer(L, "oX", S_IXOTH);
+    /* fnmatch flags */
+#ifdef FNM_NOESCAPE
+    set_integer(L, "FNM_NOESCAPE", FNM_NOESCAPE);
+#endif
+#ifdef FNM_PATHNAME
+    set_integer(L, "FNM_PATHNAME", FNM_PATHNAME);
+#endif
+#ifdef FNM_PERIOD
+    set_integer(L, "FNM_PERIOD", FNM_PERIOD);
+#endif
+#ifdef FNM_FILE_NAME
+    set_integer(L, "FNM_FILE_NAME", FNM_FILE_NAME);
+#endif
+#ifdef FNM_LEADING_DIR
+    set_integer(L, "FNM_LEADING_DIR", FNM_LEADING_DIR);
+#endif
+#ifdef FNM_CASEFOLD
+    set_integer(L, "FNM_CASEFOLD", FNM_CASEFOLD);
+#endif
+#ifdef FNM_EXTMATCH
+    set_integer(L, "FNM_EXTMATCH", FNM_EXTMATCH);
+#endif
     return 1;
 }

tests/luax-tests/fs_test.lua

@@ -103,6 +103,30 @@ local function fs_test(tmp)
         eq(fs.glob():sort(),{"bar","bar.txt","foo","foo.txt", "level1"})
         eq(fs.glob("*.txt"):sort(),{"bar.txt","foo.txt"})
     end
+    do
+        eq(fs.fnmatch("*.txt", "foo.txt"), true)
+        eq(fs.fnmatch("*.txt", "foo.md"), false)
+        eq(fs.fnmatch("*.txt", "foo.md"), false)
+
+        eq(fs.fnmatch("ab/*/cd/*.txt", "ab/xy/cd/foo.txt"), true)
+        eq(fs.fnmatch("ab/*/cd/*.txt", "ab/xy/cd/foo.md"), false)
+
+        eq(fs.fnmatch("*/*.txt", "a/foo.txt"), true)
+        eq(fs.fnmatch("*/*.txt", "a/foo.md"), false)
+        eq(fs.fnmatch("*/*.txt", "a/b/foo.txt"), true)
+        eq(fs.fnmatch("*/*/*.txt", "a/b/foo.txt"), true)
+
+        if sys.os == "linux" and sys.libc == "gnu" then
+            eq(type(fs.FNM_NOESCAPE), "number")
+            eq(type(fs.FNM_PATHNAME), "number")
+            eq(type(fs.FNM_PERIOD), "number")
+            eq(type(fs.FNM_FILE_NAME), "number")
+            eq(type(fs.FNM_LEADING_DIR), "number")
+            eq(type(fs.FNM_CASEFOLD), "number")
+            eq(type(fs.FNM_EXTMATCH), "number")
+        end
+
+    end
     if sys.libc == "gnu" or sys.libc == "musl" then
         fs.chdir(cwd)
         eq(fs.dir(tmp):sort(),{"bar","bar.txt","foo","foo.txt", "level1"})