Edited some module descriptions

[deark.git] / src / deark-user.c

// This file is part of Deark.
// Copyright (C) 2016 Jason Summers
// See the file COPYING for terms of use.

// deark-user.c
//
// Functions in this file can be called by deark-cmd.c, but should not be called
// by anything in the library or modules (use deark-util.c instead).

#define DE_NOT_IN_MODULE
#include "deark-config.h"
#include "deark-private.h"
#include "deark-user.h"

#define DE_DEFAULT_MAX_FILE_SIZE 0x280000000LL // 10GiB
#define DE_DEFAULT_MAX_TOTAL_OUTPUT_SIZE 0x3c0000000LL // 15GiB
#define DE_DEFAULT_MAX_IMAGE_DIMENSION 10000
#define DE_DEFAULT_MAX_OUTPUT_FILES 1000 // Limit for direct output (not ZIP)
#define DE_MAX_OUTPUT_FILES_HARD_LIMIT 250000

// Returns the best module to use, by looking at the file contents, etc.
static struct deark_module_info *detect_module_for_file(deark *c, int *errflag)
{
        int i;
        int result;
        int orig_errcount;
        struct deark_module_info *best_module = NULL;

        *errflag = 0;
        if(!c->detection_data) {
                c->detection_data = de_malloc(c, sizeof(struct de_detection_data_struct));
        }

        // This value is made available to modules' identification functions, so
        // that they can potentially skip expensive tests that cannot possibly return
        // a high enough confidence.
        c->detection_data->best_confidence_so_far = 0;

        orig_errcount = c->error_count;
        for(i=0; i<c->num_modules; i++) {
                if(c->module_info[i].identify_fn==NULL) continue;

                // If autodetect is disabled for this module, and its autodetect routine
                // doesn't do anything that may be needed by other modules, don't bother
                // to run this module's autodetection.
                if((c->module_info[i].flags & DE_MODFLAG_DISABLEDETECT) &&
                        !(c->module_info[i].flags & DE_MODFLAG_SHAREDDETECTION))
                {
                        continue;
                }

                result = c->module_info[i].identify_fn(c);

                if(c->error_count > orig_errcount) {
                        // Detection routines don't normally produce errors. If one does,
                        // it's probably an internal error, or other serious problem.
                        *errflag = 1;
                        return NULL;
                }

                if(c->module_info[i].flags & DE_MODFLAG_DISABLEDETECT) {
                        // Ignore results of autodetection.
                        continue;
                }

                if(result <= c->detection_data->best_confidence_so_far) continue;

                // This is the best result so far.
                c->detection_data->best_confidence_so_far = result;
                best_module = &c->module_info[i];
                if(c->detection_data->best_confidence_so_far>=100) break;
        }

        return best_module;
}

struct sort_data_struct {
        deark *c;
        int module_index;
};

static int module_compare_fn(const void *a, const void *b)
{
        struct sort_data_struct *m1, *m2;
        deark *c;

        m1 = (struct sort_data_struct *)a;
        m2 = (struct sort_data_struct *)b;
        c = m1->c;
        return de_strcasecmp(c->module_info[m1->module_index].id,
                c->module_info[m2->module_index].id);
}

void de_print_module_list(deark *c)
{
        int i, k;
        struct sort_data_struct *sort_data = NULL;

        de_register_modules(c);

        // An index to the modules. Will be sorted by name.
        sort_data = de_mallocarray(c, c->num_modules, sizeof(struct sort_data_struct));

        for(k=0; k<c->num_modules; k++) {
                sort_data[k].c = c;
                sort_data[k].module_index = k;
        }

        qsort((void*)sort_data, (size_t)c->num_modules, sizeof(struct sort_data_struct),
                module_compare_fn);

        for(k=0; k<c->num_modules; k++) {
                const char *desc;
                i = sort_data[k].module_index;
                if(!c->module_info[i].id) continue;
                if(c->extract_level<2) {
                        if(c->module_info[i].flags & DE_MODFLAG_HIDDEN) continue;
                        if(c->module_info[i].flags & DE_MODFLAG_NONWORKING) continue;
                }
                desc = c->module_info[i].desc ? c->module_info[i].desc : "-";
                de_printf(c, DE_MSGTYPE_MESSAGE, "%-14s %s\n", c->module_info[i].id, desc);
        }

        de_free(c, sort_data);
}

static void do_modhelp_internal(deark *c, struct deark_module_info *module_to_use)
{
        int k;

        if(!module_to_use) goto done;
        de_msg(c, "Module: %s", module_to_use->id);

        for(k=0; k<DE_MAX_MODULE_ALIASES; k++) {
                if(module_to_use->id_alias[k]) {
                        de_msg(c, "Alias: %s", module_to_use->id_alias[k]);
                }
                else {
                        break;
                }
        }

        if(module_to_use->desc) {
                de_msg(c, "Description: %s", module_to_use->desc);
        }
        if(module_to_use->desc2) {
                de_msg(c, "Other notes: %s", module_to_use->desc2);
        }

        if(!module_to_use->help_fn) {
                de_msg(c, "No help available for module \"%s\"", module_to_use->id);
                goto done;
        }

        de_msg(c, "Help for module \"%s\":", module_to_use->id);
        module_to_use->help_fn(c);

done:
        ;
}

static void do_modhelp(deark *c)
{
        struct deark_module_info *module_to_use = NULL;

        de_register_modules(c);
        module_to_use = de_get_module_by_id(c, c->input_format_req);
        if(!module_to_use) {
                de_err(c, "Unknown module \"%s\"", c->input_format_req);
                goto done;
        }

        if(de_strcmp(c->input_format_req, module_to_use->id)) {
                de_msg(c, "\"%s\" is an alias for module \"%s\"",
                        c->input_format_req, module_to_use->id);
        }

        do_modhelp_internal(c, module_to_use);

done:
        ;
}

void de_register_modules(deark *c)
{
        // The real register_modules function (de_register_modules_internal) is
        // only called indirectly, to help simplify dependencies.
        if(!c->module_register_fn) {
                de_internal_err_fatal(c, "module_register_fn not set");
                return;
        }
        c->module_register_fn(c);
}

static void open_extrlist(deark *c)
{
        unsigned int flags = 0;

        if(c->extrlist_dbuf || !c->extrlist_filename) return;

        if(de_get_ext_option(c, "extrlist:append")) {
                flags |= 0x1;
        }

        c->extrlist_dbuf = dbuf_create_unmanaged_file(c, c->extrlist_filename,
                DE_OVERWRITEMODE_STANDARD, flags);
}

// Returns 0 on "serious" error; e.g. input file not found.
int de_run(deark *c)
{
        dbuf *orig_ifile = NULL;
        dbuf *subfile = NULL;
        i64 subfile_size;
        struct deark_module_info *module_to_use = NULL;
        int module_was_autodetected = 0;
        int moddisp;
        int subdirs_opt;
        int keepdirentries_opt;
        de_module_params *mparams = NULL;
        de_ucstring *friendly_infn = NULL;

        if(c->modhelp_req && c->input_format_req) {
                do_modhelp(c);
                goto done;
        }

        if(c->extrlist_filename) {
                open_extrlist(c);
                if(c->serious_error_flag) goto done;
        }

        friendly_infn = ucstring_create(c);

        if(c->input_style==DE_INPUTSTYLE_STDIN) {
                ucstring_append_sz(friendly_infn, "[stdin]", DE_ENCODING_LATIN1);
        }
        else {
                if(!c->input_filename) {
                        de_internal_err_nonfatal(c, "Input file not set");
                        c->serious_error_flag = 1;
                        goto done;
                }
                ucstring_append_sz(friendly_infn, c->input_filename, DE_ENCODING_UTF8);
        }

        de_register_modules(c);

        if(c->input_format_req) {
                module_to_use = de_get_module_by_id(c, c->input_format_req);
                if(!module_to_use) {
                        de_err(c, "Unknown module \"%s\"", c->input_format_req);
                        c->serious_error_flag = 1;
                        goto done;
                }
        }

        if(c->slice_size_req_valid) {
                de_dbg(c, "Input file: %s[%d,%d]", ucstring_getpsz_d(friendly_infn),
                        (int)c->slice_start_req, (int)c->slice_size_req);
        }
        else if(c->slice_start_req) {
                de_dbg(c, "Input file: %s[%d]", ucstring_getpsz_d(friendly_infn),
                        (int)c->slice_start_req);
        }
        else {
                de_dbg(c, "Input file: %s", ucstring_getpsz_d(friendly_infn));
        }

        if(c->input_style==DE_INPUTSTYLE_STDIN) {
                orig_ifile = dbuf_open_input_stdin(c);
        }
        else {
                orig_ifile = dbuf_open_input_file(c, c->input_filename);

                if(orig_ifile && orig_ifile->btype==DBUF_TYPE_FIFO) {
                        // Only now do we know that the input "file" is a named pipe.
                        // Set a flag to remember that the input filename does not
                        // reflect the file format.
                        c->suppress_detection_by_filename = 1;
                }
        }
        if(!orig_ifile) {
                goto done;
        }

        c->infile = orig_ifile;

        // If we are only supposed to look at a segment of the original file,
        // do that by creating a child dbuf, using dbuf_open_input_subfile().
        if(c->slice_start_req>0 || c->slice_size_req_valid) {
                if(c->slice_size_req_valid)
                        subfile_size = c->slice_size_req;
                else
                        subfile_size = c->infile->len - c->slice_start_req;
                subfile = dbuf_open_input_subfile(c->infile, c->slice_start_req, subfile_size);
                c->infile = subfile;
        }

        if(!module_to_use) {
                int errflag;

                module_to_use = detect_module_for_file(c, &errflag);
                if(errflag) goto done;
                module_was_autodetected = 1;
        }

        if(!module_to_use) {
                if(c->infile->len==0)
                        de_err(c, "Unknown or unsupported file format (empty file)");
                else
                        de_err(c, "Unknown or unsupported file format");
                goto done;
        }

        if(c->modhelp_req && module_was_autodetected &&
                module_to_use->unique_id!=1) // id 1 == "unsupported"
        {
                do_modhelp_internal(c, module_to_use);
                goto done;
        }

        de_info(c, "Module: %s", module_to_use->id);

        if(module_was_autodetected && (module_to_use->flags&DE_MODFLAG_SECURITYWARNING)) {
                de_err(c, "The %s module has not been audited for security. There is a "
                        "greater than average chance that it is unsafe to use with untrusted "
                        "input files. Use \"-m %s\" to confirm that you want to use it.",
                        module_to_use->id, module_to_use->id);
                c->serious_error_flag = 1;
                goto done;
        }

        if(module_to_use->flags&DE_MODFLAG_NONWORKING) {
                de_warn(c, "The %s module is considered to be incomplete, and may "
                        "not work properly. Caveat emptor.",
                        module_to_use->id);
        }

        if(c->identify_only) {
                // Stop here, unless we're using the "unsupported" module.
                if(module_to_use->unique_id!=1) {
                        goto done;
                }
        }

        de_dbg2(c, "file size: %" I64_FMT "", c->infile->len);

        if(c->output_style==DE_OUTPUTSTYLE_ARCHIVE) {
                subdirs_opt = de_get_ext_option_bool(c, "archive:subdirs", -1);
                if(subdirs_opt<0) {
                        // By default, for archive output, enable subdirs unless -o was used.
                        if(!c->base_output_filename) {
                                c->allow_subdirs = 1;
                        }
                }
                else {
                        c->allow_subdirs = subdirs_opt?1:0;
                }
        }

        keepdirentries_opt = de_get_ext_option_bool(c, "keepdirentries", -1);
        if(keepdirentries_opt<0) {
                // By default, only keep dir entries if there is some way that
                // files can be present in such a subdir.
                c->keep_dir_entries = (u8)(
                        (c->output_style==DE_OUTPUTSTYLE_ARCHIVE) &&
                        c->allow_subdirs &&
                        (!c->base_output_filename));
        }
        else {
                c->keep_dir_entries = keepdirentries_opt?1:0;
        }

        if(c->output_style==DE_OUTPUTSTYLE_ARCHIVE) {
                const char *s_opt;

                s_opt = de_get_ext_option(c, "archive:timestamp");
                if(s_opt) {
                        c->reproducible_output = 1;
                        de_unix_time_to_timestamp(de_atoi64(s_opt), &c->reproducible_timestamp, 0x1);
                        if(!c->reproducible_timestamp.is_valid) {
                                // Timestamp out of range? Note: Supported range is
                                //  -11644473599 ( 1601-01-01 00:00:01) through
                                //  910692730085 (30828-09-14 02:48:05)
                                c->reproducible_output = 0;
                        }
                }
                else {
                        if(de_get_ext_option(c, "archive:repro")) {
                                c->reproducible_output = 1;
                        }
                }
        }

        if(c->output_style==DE_OUTPUTSTYLE_DIRECT &&
                c->max_output_files > DE_DEFAULT_MAX_OUTPUT_FILES &&
                !c->list_mode && !c->user_set_max_output_files)
        {
                c->max_output_files = DE_DEFAULT_MAX_OUTPUT_FILES;
        }

        // If we're writing to a zip file, we normally defer creating that zip file
        // until we find a file to extract, so that we never create a zip file with
        // no member files.
        // But if the zip "file" is going to stdout, we'll make sure we produce zip
        // output, even if it has no member files.
        if(c->output_style==DE_OUTPUTSTYLE_ARCHIVE && c->archive_to_stdout) {
                if(!de_archive_initialize(c)) {
                        goto done;
                }
        }

        if(c->list_mode) {
                if(de_get_ext_option_bool(c, "list:fileid", 0)) {
                        c->list_mode_include_file_id = 1;
                }
        }

        if(c->modcodes_req) {
                if(!mparams)
                        mparams = de_malloc(c, sizeof(de_module_params));
                // This is a hack, mainly for developer use. It lets the user set the
                // "module codes" string from the command line, so that some modules
                // can be run in special modes. For example, you can run the psd module
                // in its "tagged blocks" mode. (If that turns out to be useful, though,
                // it would be better to make it available via an "-opt" option, or
                // even a new module.)
                mparams->in_params.codes = c->modcodes_req;
        }

        if(module_was_autodetected)
                moddisp = DE_MODDISP_AUTODETECT;
        else
                moddisp = DE_MODDISP_EXPLICIT;

        if(!de_run_module(c, module_to_use, mparams, moddisp)) {
                goto done;
        }

        // The DE_MODFLAG_NOEXTRACT flag means the module is not expected to extract
        // any files.
        if(c->num_files_extracted==0 && c->error_count==0 &&
                !(module_to_use->flags&DE_MODFLAG_NOEXTRACT))
        {
                de_info(c, "No files found to extract!");
        }

done:
        if(c->extrlist_dbuf) { dbuf_close(c->extrlist_dbuf); c->extrlist_dbuf=NULL; }
        ucstring_destroy(friendly_infn);
        if(subfile) dbuf_close(subfile);
        if(orig_ifile) dbuf_close(orig_ifile);
        de_free(c, mparams);
        return c->serious_error_flag ? 0 : 1;
}

deark *de_create_internal(void)
{
        deark *c;
        c = de_malloc(NULL,sizeof(deark));
        c->show_infomessages = 1;
        c->show_warnings = 1;
        c->write_bom = 1;
        c->write_density = 1;
        c->filenames_from_file = 1;
        c->preserve_file_times = 1;
        c->preserve_file_times_archives = 1;
        c->preserve_file_times_internal = 1;
        c->max_output_files = DE_MAX_OUTPUT_FILES_HARD_LIMIT;
        c->max_image_dimension = DE_DEFAULT_MAX_IMAGE_DIMENSION;
        c->max_output_file_size = DE_DEFAULT_MAX_FILE_SIZE;
        c->max_total_output_size = DE_DEFAULT_MAX_TOTAL_OUTPUT_SIZE;
        c->current_time.is_valid = 0;
        c->can_decode_fltpt = -1; // = unknown
        c->host_is_le = -1; // = unknown
        c->input_encoding = DE_ENCODING_UNKNOWN;
        return c;
}

void de_destroy(deark *c)
{
        i64 i;

        if(!c) return;
        if(c->zip_data) { de_zip_close_file(c); }
        if(c->tar_data) { de_tar_close_file(c); }
        if(c->extrlist_dbuf) { dbuf_close(c->extrlist_dbuf); }
        for(i=0; i<c->num_ext_options; i++) {
                de_free(c, c->ext_option[i].name);
                de_free(c, c->ext_option[i].val);
        }
        if(c->base_output_filename) { de_free(c, c->base_output_filename); }
        if(c->special_1st_filename) { de_free(c, c->special_1st_filename); }
        if(c->output_archive_filename) { de_free(c, c->output_archive_filename); }
        if(c->extrlist_filename) { de_free(c, c->extrlist_filename); }
        if(c->detection_data) { de_free(c, c->detection_data); }
        de_free(c, c->module_info);
        de_free(NULL,c);
}

void de_set_userdata(deark *c, void *x)
{
        c->userdata = x;
}

void *de_get_userdata(deark *c)
{
        return c->userdata;
}

void de_set_messages_callback(deark *c, de_msgfn_type fn)
{
        c->msgfn = fn;
}

void de_set_special_messages_callback(deark *c, de_specialmsgfn_type fn)
{
        c->specialmsgfn = fn;
}

void de_set_fatalerror_callback(deark *c, de_fatalerrorfn_type fn)
{
        c->fatalerrorfn = fn;
}

static int is_pathsep(i32 ch)
{
        if(ch=='/') return 1;
#ifdef DE_WINDOWS
        if(ch=='\\') return 1;
#endif
        return 0;
}

#ifdef DE_WINDOWS
#define DE_PATHSEP '\\'
#else
#define DE_PATHSEP '/'
#endif

static const char *get_basename_ptr(const char *fn)
{
        size_t i;
        const char *basenameptr = fn;

        for(i=0; fn[i]; i++) {
                if(is_pathsep(fn[i])) {
                        basenameptr = &fn[i+1];
                }
        }
        return basenameptr;
}

static i32 ucstring_char_at(de_ucstring *s, i64 pos)
{
        if(!s) return 0;
        if(pos>=0 && pos<s->len) return s->str[pos];
        return 0;
}

#ifdef DE_WINDOWS
static void backslashes_to_slashes(de_ucstring *s)
{
        i64 i;

        for(i=0; i<s->len; i++) {
                if(s->str[i]=='\\') {
                        s->str[i] = '/';
                }
        }
}
#endif

// Construct a basename for output files, or a filename for archives.
// flags:
//  0x1 = use base filename only
//  0x2 = remove path separators
//  0x4 = this is an "internal" filename for a zip/tar archive
// Returns an allocated string, which the caller must eventually free.
// Returns NULL if it can't make a decent filename.
static char *make_output_filename(deark *c, const char *dirname, const char *fn,
        const char *suffix, unsigned int flags)
{
        char *newfn = NULL;
        const char *fn_part;
        size_t newfn_alloc;
        de_ucstring *tmps = NULL;
        i64 fnpartpos;

        tmps = ucstring_create(c);

        if(dirname && dirname[0]) {
                ucstring_append_sz(tmps, dirname, DE_ENCODING_UTF8);
                if(!is_pathsep(ucstring_char_at(tmps, tmps->len-1))) {
                        ucstring_append_char(tmps, DE_PATHSEP);
                }
        }

        fnpartpos = tmps->len;

        if(flags & 0x1) {
                // Use base filename only
                fn_part = get_basename_ptr(fn);
        }
        else {
                fn_part = fn;
        }
        if(fn_part) {
                ucstring_append_sz(tmps, fn_part, DE_ENCODING_UTF8);
        }

        if(tmps->len <= fnpartpos) {
                // Disallow empty filename
                ucstring_append_sz(tmps, "_", DE_ENCODING_LATIN1);
        }

        if(suffix) {
                ucstring_append_sz(tmps, suffix, DE_ENCODING_UTF8);
        }

        if(flags & 0x2) {
                // Remove path separators; sanitize
                i64 i;

                for(i=fnpartpos; i<tmps->len; i++) {
                        if(is_pathsep(tmps->str[i])) {
                                tmps->str[i] = '_';
                        }

                        if(i==fnpartpos && tmps->str[i]=='.') {
                                tmps->str[i] = '_';
                        }
                }
        }

#ifdef DE_WINDOWS
        if(flags & 0x4) {
                // When a filename-like option is supplied on the command line, there are
                // cases where we can't be agnostic about which characters are path
                // separators. One of them is when that name is written to an archive
                // (zip/tar) file.
                // Our rule is that, for Windows builds, both "\" and "/" are path
                // separators. For Unix builds, only "/" is, and "\" will be treated as
                // an ordinary filename character, if allowed by the archive format.
                // This difference in behavior on different platforms is unfortunate, but
                // I think it's the least bad thing to do.
                backslashes_to_slashes(tmps);
        }
#endif

        // Don't allow empty filename
        if(tmps->len<1) goto done;

        newfn_alloc = (size_t)ucstring_count_utf8_bytes(tmps) + 1;
        newfn = de_malloc(c, newfn_alloc);
        ucstring_to_sz(tmps, newfn, newfn_alloc, 0, DE_ENCODING_UTF8);

done:
        ucstring_destroy(tmps);
        return newfn;
}

// Must call de_set_output_style() before this, if at all.
// flags:
//  0x1 = use base filename only
//  0x2 = remove path separators
void de_set_output_filename_pattern(deark *c, const char *dirname, const char *fn,
        unsigned int flags)
{
        if(c->base_output_filename) de_free(c, c->base_output_filename);
        c->base_output_filename = NULL;
        if(!fn && !dirname) return;
        if(!fn) fn = "output";
        if(c->output_style==DE_OUTPUTSTYLE_ARCHIVE) {
                flags |= 0x4;
        }
        c->base_output_filename = make_output_filename(c, dirname, fn, NULL, flags);
}

// Use exactly fn for the first output file (no ".000.")
// Must call de_set_output_style() before this, if at all.
void de_set_output_special_1st_filename(deark *c, const char *dirname, const char *fn)
{
        if(c->special_1st_filename) {
                de_free(c, c->special_1st_filename);
                c->special_1st_filename = NULL;
        }
        if(fn) {
                UI flags = 0;

                if(c->output_style==DE_OUTPUTSTYLE_ARCHIVE) {
                        flags |= 0x4;
                }

                c->special_1st_filename = make_output_filename(c, dirname, fn, NULL, flags);
        }
}

// If flags&0x10, configure the archive file to be written to stdout.
// 0x20 = Append ".zip"/".tar" (must have already called de_set_output_style())
//  0x1 = use base filename only
//  0x2 = remove path separators
void de_set_output_archive_filename(deark *c, const char *dname, const char *fn,
        unsigned int flags)
{
        const char *suffix = NULL;
        if(c->output_archive_filename) de_free(c, c->output_archive_filename);

        if(flags&0x10) {
                c->archive_to_stdout = 1;
                return;
        }

        if((flags & 0x20) && c->output_style==DE_OUTPUTSTYLE_ARCHIVE) {
                if(c->archive_fmt==DE_ARCHIVEFMT_ZIP) {
                        suffix = ".zip";
                }
                else if(c->archive_fmt==DE_ARCHIVEFMT_TAR) {
                        suffix = ".tar";
                }
                else {
                        suffix = ".err";
                }
        }

        c->output_archive_filename = make_output_filename(c, dname, fn, suffix, flags);
}

void de_set_extrlist_filename(deark *c, const char *fn)
{
        if(c->extrlist_filename) de_free(c, c->extrlist_filename);
        c->extrlist_filename = NULL;
        if(fn) {
                c->extrlist_filename = de_strdup(c, fn);
        }
}

void de_set_std_option_int(deark *c, enum de_stdoptions_enum o, int x)
{
        switch(o) {
        case DE_STDOPT_DEBUG_LEVEL:
                c->debug_level = x;
                break;
        case DE_STDOPT_EXTRACT_POLICY:
                c->extract_policy = x;
                break;
        case DE_STDOPT_EXTRACT_LEVEL:
                c->extract_level = x;
                break;
        case DE_STDOPT_LISTMODE:
                c->list_mode = x?1:0;
                break;
        case DE_STDOPT_WANT_MODHELP:
                c->modhelp_req = x?1:0;
                break;
        case DE_STDOPT_ID_MODE:
                c->identify_only = x?1:0;
                break;
        case DE_STDOPT_WARNINGS:
                c->show_warnings = x;
                break;
        case DE_STDOPT_INFOMESSAGES:
                c->show_infomessages = x;
                break;
        case DE_STDOPT_WRITE_BOM:
                c->write_bom = (u8)x;
                break;
        case DE_STDOPT_WRITE_DENSITY:
                c->write_density = (u8)x;
                break;
        case DE_STDOPT_ASCII_HTML:
                c->ascii_html = (u8)x;
                break;
        case DE_STDOPT_FILENAMES_FROM_FILE:
                c->filenames_from_file = (u8)x;
                break;
        case DE_STDOPT_OVERWRITE_MODE:
                c->overwrite_mode = x;
                break;
        case DE_STDOPT_PADPIX:
                c->padpix = (u8)x;
                break;
        default:
                de_internal_err_fatal(c, "set_std_option");
        }
}

void de_set_input_style(deark *c, int x)
{
        c->input_style = x;
}

void de_set_input_filename(deark *c, const char *fn)
{
        c->input_filename = fn;
}

int de_set_input_encoding(deark *c, const char *encname, int reserved)
{
        de_encoding enc;

        enc = de_encoding_name_to_code(encname);
        if(enc==DE_ENCODING_UNKNOWN) {
                return 0;
        }
        c->input_encoding = enc;
        return 1;
}

// A hint as to the timezone of local-time timestamps in input files.
// In hours east of UTC.
void de_set_input_timezone(deark *c, i64 tzoffs_seconds)
{
        c->input_tz_offs_seconds = tzoffs_seconds;
}

void de_set_input_file_slice_start(deark *c, i64 n)
{
        c->slice_start_req = n;
}

void de_set_input_file_slice_size(deark *c, i64 n)
{
        c->slice_size_req = n;
        c->slice_size_req_valid = 1;
}

void de_set_output_style(deark *c, int x, int subtype)
{
        c->output_style = x;
        if(c->output_style==DE_OUTPUTSTYLE_ARCHIVE) {
                c->archive_fmt = subtype;
        }
        else {
                c->archive_fmt = 0;
        }
}

void de_set_dprefix(deark *c, const char *s)
{
        c->dprefix = s;
}

void de_set_first_output_file(deark *c, int x)
{
        c->first_output_file = x;
}

void de_set_max_output_files(deark *c, i64 n)
{
        if(n>DE_MAX_OUTPUT_FILES_HARD_LIMIT) {
                c->max_output_files = DE_MAX_OUTPUT_FILES_HARD_LIMIT;
        }
        else if(n<0) {
                c->max_output_files = 0;
        }
        else {
                c->max_output_files = (int)n;
        }
        c->user_set_max_output_files = 1;
}

void de_set_max_output_file_size(deark *c, i64 n)
{
        if(n<0) n=0;
        c->max_output_file_size = n;
        if(c->max_total_output_size < n) {
                c->max_total_output_size = n;
        }
}

void de_set_max_total_output_size(deark *c, i64 n)
{
        if(n<0) n=0;
        c->max_total_output_size = n;
}

void de_set_max_image_dimension(deark *c, i64 n)
{
        if(n<0) n=0;
        else if (n>0x7fffffff) n=0x7fffffff;
        c->max_image_dimension = n;
}

void de_set_preserve_file_times(deark *c, int setting, int x)
{
        if(setting==0) {
                // For files written directly to the filesystem.
                c->preserve_file_times = x?1:0;
        }
        else if(setting==1) {
                // For member files written to .zip/.tar files.
                // I can't think of a good reason why a user would want to disable
                // this, but it's allowed for consistency, and it doesn't hurt
                // anything.
                c->preserve_file_times_archives = x?1:0;
        }
        else if(setting==2) {
                // For the tIME chunk in PNG files we generate, and other internal timestamps.
                // (Not currently used.)
                // TODO: I'm undecided about whether this should be a user option, or
                // just always be on.
                // TODO: If we allow this setting to be turned off, it would be
                // consistent to rename it, and use it for all "converted" formats,
                // including e.g. the "Date" header item in ANSI Art files converted
                // to HTML.
                c->preserve_file_times_internal = x?1:0;
        }
}

void de_set_ext_option(deark *c, const char *name, const char *val)
{
        int n;

        n = c->num_ext_options;
        if(n>=DE_MAX_EXT_OPTIONS) return;
        if(!name || !val) return;

        c->ext_option[n].name = de_strdup(c, name);
        c->ext_option[n].val = de_strdup(c, val);
        c->num_ext_options++;
}

void de_set_input_format(deark *c, const char *fmtname)
{
        c->input_format_req = fmtname;
}

void de_set_module_init_codes(deark *c, const char *codes)
{
        c->modcodes_req = codes;
}

// invert=0: Disable the mods in the list
// invert=1: Disable all mods not in the list
void de_set_disable_mods(deark *c, const char *s, int invert)
{
        if(invert==0) {
                c->disablemods_string = s;
        }
        else {
                c->onlymods_string = s;
        }
}

// invert=0: Disable autodetection of the mods in the list
// invert=1: Disable autodetection of all mods not in the list
void de_set_disable_moddetect(deark *c, const char *s, int invert)
{
        if(invert==0) {
                c->nodetectmods_string = s;
        }
        else {
                c->onlydetectmods_string = s;
        }
}