cc9d621dd0
The commit c68b7d236 (commands/test: Stack overflow due to unlimited recursion depth) added recursion depth tests to the test command. But in the error case it decrements the pointer to the depth value instead of the value itself. Fix it. Fixes: c68b7d236 (commands/test: Stack overflow due to unlimited recursion depth) Signed-off-by: Thomas Frauendorfer | Miray Software <tf@miray.de> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
471 lines
12 KiB
C
471 lines
12 KiB
C
/* test.c -- The test command.. */
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2005,2007,2009 Free Software Foundation, Inc.
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*
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <grub/dl.h>
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#include <grub/misc.h>
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#include <grub/mm.h>
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#include <grub/env.h>
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#include <grub/fs.h>
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#include <grub/device.h>
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#include <grub/file.h>
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#include <grub/command.h>
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#include <grub/i18n.h>
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GRUB_MOD_LICENSE ("GPLv3+");
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/* Set a limit on recursion to avoid stack overflow. */
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#define MAX_TEST_RECURSION_DEPTH 100
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/* A simple implementation for signed numbers. */
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static int
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grub_strtosl (char *arg, const char ** const end, int base)
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{
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if (arg[0] == '-')
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return -grub_strtoul (arg + 1, end, base);
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return grub_strtoul (arg, end, base);
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}
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/* Context for test_parse. */
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struct test_parse_ctx
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{
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int invert;
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int or, and;
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int file_exists;
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struct grub_dirhook_info file_info;
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char *filename;
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};
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/* Take care of discarding and inverting. */
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static void
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update_val (int val, struct test_parse_ctx *ctx)
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{
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ctx->and = ctx->and && (ctx->invert ? ! val : val);
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ctx->invert = 0;
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}
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/* A hook for iterating directories. */
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static int
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find_file (const char *cur_filename, const struct grub_dirhook_info *info,
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void *data)
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{
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struct test_parse_ctx *ctx = data;
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if ((info->case_insensitive ? grub_strcasecmp (cur_filename, ctx->filename)
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: grub_strcmp (cur_filename, ctx->filename)) == 0)
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{
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ctx->file_info = *info;
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ctx->file_exists = 1;
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return 1;
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}
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return 0;
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}
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/* Check if file exists and fetch its information. */
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static void
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get_fileinfo (char *path, struct test_parse_ctx *ctx)
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{
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char *pathname;
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char *device_name;
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grub_fs_t fs;
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grub_device_t dev;
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ctx->file_exists = 0;
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device_name = grub_file_get_device_name (path);
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dev = grub_device_open (device_name);
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if (! dev)
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{
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grub_free (device_name);
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return;
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}
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fs = grub_fs_probe (dev);
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if (! fs)
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{
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grub_free (device_name);
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grub_device_close (dev);
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return;
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}
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pathname = grub_strchr (path, ')');
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if (! pathname)
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pathname = path;
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else
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pathname++;
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/* Remove trailing '/'. */
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while (*pathname && pathname[grub_strlen (pathname) - 1] == '/')
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pathname[grub_strlen (pathname) - 1] = 0;
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/* Split into path and filename. */
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ctx->filename = grub_strrchr (pathname, '/');
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if (! ctx->filename)
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{
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path = grub_strdup ("/");
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ctx->filename = pathname;
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}
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else
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{
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ctx->filename++;
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path = grub_strdup (pathname);
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path[ctx->filename - pathname] = 0;
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}
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/* It's the whole device. */
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if (! *pathname)
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{
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ctx->file_exists = 1;
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grub_memset (&ctx->file_info, 0, sizeof (ctx->file_info));
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/* Root is always a directory. */
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ctx->file_info.dir = 1;
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/* Fetch writing time. */
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ctx->file_info.mtimeset = 0;
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if (fs->fs_mtime)
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{
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if (! fs->fs_mtime (dev, &ctx->file_info.mtime))
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ctx->file_info.mtimeset = 1;
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grub_errno = GRUB_ERR_NONE;
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}
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}
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else
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(fs->fs_dir) (dev, path, find_file, ctx);
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grub_device_close (dev);
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grub_free (path);
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grub_free (device_name);
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}
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/* Parse a test expression starting from *argn. */
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static int
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test_parse (char **args, int *argn, int argc, int *depth)
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{
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struct test_parse_ctx ctx = {
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.and = 1,
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.or = 0,
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.invert = 0
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};
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/* Here we have the real parsing. */
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while (*argn < argc)
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{
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/* First try 3 argument tests. */
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if (*argn + 2 < argc)
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{
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/* String tests. */
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if (grub_strcmp (args[*argn + 1], "=") == 0
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|| grub_strcmp (args[*argn + 1], "==") == 0)
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{
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update_val (grub_strcmp (args[*argn], args[*argn + 2]) == 0,
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&ctx);
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(*argn) += 3;
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continue;
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}
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if (grub_strcmp (args[*argn + 1], "!=") == 0)
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{
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update_val (grub_strcmp (args[*argn], args[*argn + 2]) != 0,
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&ctx);
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(*argn) += 3;
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continue;
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}
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/* GRUB extension: lexicographical sorting. */
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if (grub_strcmp (args[*argn + 1], "<") == 0)
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{
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update_val (grub_strcmp (args[*argn], args[*argn + 2]) < 0,
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&ctx);
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(*argn) += 3;
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continue;
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}
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if (grub_strcmp (args[*argn + 1], "<=") == 0)
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{
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update_val (grub_strcmp (args[*argn], args[*argn + 2]) <= 0,
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&ctx);
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(*argn) += 3;
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continue;
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}
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if (grub_strcmp (args[*argn + 1], ">") == 0)
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{
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update_val (grub_strcmp (args[*argn], args[*argn + 2]) > 0,
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&ctx);
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(*argn) += 3;
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continue;
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}
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if (grub_strcmp (args[*argn + 1], ">=") == 0)
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{
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update_val (grub_strcmp (args[*argn], args[*argn + 2]) >= 0,
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&ctx);
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(*argn) += 3;
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continue;
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}
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/* Number tests. */
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if (grub_strcmp (args[*argn + 1], "-eq") == 0)
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{
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update_val (grub_strtosl (args[*argn], 0, 0)
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== grub_strtosl (args[*argn + 2], 0, 0), &ctx);
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(*argn) += 3;
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continue;
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}
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if (grub_strcmp (args[*argn + 1], "-ge") == 0)
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{
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update_val (grub_strtosl (args[*argn], 0, 0)
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>= grub_strtosl (args[*argn + 2], 0, 0), &ctx);
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(*argn) += 3;
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continue;
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}
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if (grub_strcmp (args[*argn + 1], "-gt") == 0)
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{
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update_val (grub_strtosl (args[*argn], 0, 0)
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> grub_strtosl (args[*argn + 2], 0, 0), &ctx);
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(*argn) += 3;
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continue;
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}
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if (grub_strcmp (args[*argn + 1], "-le") == 0)
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{
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update_val (grub_strtosl (args[*argn], 0, 0)
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<= grub_strtosl (args[*argn + 2], 0, 0), &ctx);
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(*argn) += 3;
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continue;
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}
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if (grub_strcmp (args[*argn + 1], "-lt") == 0)
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{
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update_val (grub_strtosl (args[*argn], 0, 0)
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< grub_strtosl (args[*argn + 2], 0, 0), &ctx);
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(*argn) += 3;
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continue;
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}
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if (grub_strcmp (args[*argn + 1], "-ne") == 0)
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{
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update_val (grub_strtosl (args[*argn], 0, 0)
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!= grub_strtosl (args[*argn + 2], 0, 0), &ctx);
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(*argn) += 3;
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continue;
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}
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/* GRUB extension: compare numbers skipping prefixes.
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Useful for comparing versions. E.g. vmlinuz-2 -plt vmlinuz-11. */
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if (grub_strcmp (args[*argn + 1], "-pgt") == 0
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|| grub_strcmp (args[*argn + 1], "-plt") == 0)
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{
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int i;
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/* Skip common prefix. */
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for (i = 0; args[*argn][i] == args[*argn + 2][i]
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&& args[*argn][i]; i++);
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/* Go the digits back. */
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i--;
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while (grub_isdigit (args[*argn][i]) && i > 0)
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i--;
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i++;
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if (grub_strcmp (args[*argn + 1], "-pgt") == 0)
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update_val (grub_strtoul (args[*argn] + i, 0, 0)
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> grub_strtoul (args[*argn + 2] + i, 0, 0), &ctx);
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else
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update_val (grub_strtoul (args[*argn] + i, 0, 0)
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< grub_strtoul (args[*argn + 2] + i, 0, 0), &ctx);
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(*argn) += 3;
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continue;
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}
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/* -nt and -ot tests. GRUB extension: when doing -?t<bias> bias
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will be added to the first mtime. */
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if (grub_memcmp (args[*argn + 1], "-nt", 3) == 0
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|| grub_memcmp (args[*argn + 1], "-ot", 3) == 0)
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{
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struct grub_dirhook_info file1;
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int file1exists;
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int bias = 0;
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/* Fetch fileinfo. */
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get_fileinfo (args[*argn], &ctx);
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file1 = ctx.file_info;
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file1exists = ctx.file_exists;
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get_fileinfo (args[*argn + 2], &ctx);
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if (args[*argn + 1][3])
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bias = grub_strtosl (args[*argn + 1] + 3, 0, 0);
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if (grub_memcmp (args[*argn + 1], "-nt", 3) == 0)
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update_val ((file1exists && ! ctx.file_exists)
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|| (file1.mtimeset && ctx.file_info.mtimeset
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&& file1.mtime + bias > ctx.file_info.mtime),
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&ctx);
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else
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update_val ((! file1exists && ctx.file_exists)
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|| (file1.mtimeset && ctx.file_info.mtimeset
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&& file1.mtime + bias < ctx.file_info.mtime),
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&ctx);
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(*argn) += 3;
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continue;
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}
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}
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/* Two-argument tests. */
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if (*argn + 1 < argc)
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{
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/* File tests. */
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if (grub_strcmp (args[*argn], "-d") == 0)
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{
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get_fileinfo (args[*argn + 1], &ctx);
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update_val (ctx.file_exists && ctx.file_info.dir, &ctx);
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(*argn) += 2;
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continue;
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}
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if (grub_strcmp (args[*argn], "-e") == 0)
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{
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get_fileinfo (args[*argn + 1], &ctx);
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update_val (ctx.file_exists, &ctx);
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(*argn) += 2;
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continue;
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}
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if (grub_strcmp (args[*argn], "-f") == 0)
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{
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get_fileinfo (args[*argn + 1], &ctx);
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/* FIXME: check for other types. */
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update_val (ctx.file_exists && ! ctx.file_info.dir, &ctx);
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(*argn) += 2;
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continue;
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}
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if (grub_strcmp (args[*argn], "-s") == 0)
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{
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grub_file_t file;
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file = grub_file_open (args[*argn + 1], GRUB_FILE_TYPE_GET_SIZE
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| GRUB_FILE_TYPE_NO_DECOMPRESS);
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update_val (file && (grub_file_size (file) != 0), &ctx);
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if (file)
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grub_file_close (file);
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grub_errno = GRUB_ERR_NONE;
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(*argn) += 2;
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continue;
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}
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/* String tests. */
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if (grub_strcmp (args[*argn], "-n") == 0)
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{
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update_val (args[*argn + 1][0], &ctx);
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(*argn) += 2;
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continue;
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}
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if (grub_strcmp (args[*argn], "-z") == 0)
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{
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update_val (! args[*argn + 1][0], &ctx);
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(*argn) += 2;
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continue;
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}
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}
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/* Special modifiers. */
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/* End of expression. return to parent. */
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if (grub_strcmp (args[*argn], ")") == 0)
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{
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(*argn)++;
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if (*depth > 0)
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(*depth)--;
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return ctx.or || ctx.and;
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}
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/* Recursively invoke if parenthesis. */
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if (grub_strcmp (args[*argn], "(") == 0)
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{
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(*argn)++;
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if (++(*depth) > MAX_TEST_RECURSION_DEPTH)
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{
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grub_error (GRUB_ERR_OUT_OF_RANGE, N_("max recursion depth exceeded"));
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(*depth)--;
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return ctx.or || ctx.and;
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}
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update_val (test_parse (args, argn, argc, depth), &ctx);
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continue;
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}
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if (grub_strcmp (args[*argn], "!") == 0)
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{
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ctx.invert = ! ctx.invert;
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(*argn)++;
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continue;
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}
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if (grub_strcmp (args[*argn], "-a") == 0)
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{
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(*argn)++;
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continue;
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}
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if (grub_strcmp (args[*argn], "-o") == 0)
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{
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ctx.or = ctx.or || ctx.and;
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ctx.and = 1;
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(*argn)++;
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continue;
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}
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/* No test found. Interpret if as just a string. */
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update_val (args[*argn][0], &ctx);
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(*argn)++;
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}
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return ctx.or || ctx.and;
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}
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static grub_err_t
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grub_cmd_test (grub_command_t cmd __attribute__ ((unused)),
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int argc, char **args)
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{
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int argn = 0;
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int depth = 0;
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if (argc >= 1 && grub_strcmp (args[argc - 1], "]") == 0)
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argc--;
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return test_parse (args, &argn, argc, &depth) ? GRUB_ERR_NONE
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: grub_error (GRUB_ERR_TEST_FAILURE, N_("false"));
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}
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static grub_command_t cmd_1, cmd_2;
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GRUB_MOD_INIT(test)
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{
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cmd_1 = grub_register_command ("[", grub_cmd_test,
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N_("EXPRESSION ]"), N_("Evaluate an expression."));
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cmd_1->flags |= GRUB_COMMAND_FLAG_EXTRACTOR;
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cmd_2 = grub_register_command ("test", grub_cmd_test,
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N_("EXPRESSION"), N_("Evaluate an expression."));
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cmd_2->flags |= GRUB_COMMAND_FLAG_EXTRACTOR;
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}
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GRUB_MOD_FINI(test)
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{
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grub_unregister_command (cmd_1);
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grub_unregister_command (cmd_2);
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}
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