systemd/src/shared/parse-argument.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include "alloc-util.h"
#include "ansi-color.h"
#include "bus-util.h"
#include "format-table.h"
#include "hostname-util.h"
#include "log.h"
#include "parse-argument.h"
#include "parse-util.h"
#include "path-util.h"
#include "signal-util.h"
#include "string-table.h"
#include "string-util.h"

/* All functions in this file emit warnings. */

int parse_boolean_argument(const char *optname, const char *s, bool *ret) {
        int r;

        /* Returns the result through *ret and the return value. */

        assert(optname);

        if (s) {
                r = parse_boolean(s);
                if (r < 0)
                        return log_error_errno(r, "Failed to parse boolean argument to '%s': %s", optname, s);

                if (ret)
                        *ret = r;
                return r;
        } else {
                /* s may be NULL. This is controlled by OPTION flags. */
                if (ret)
                        *ret = true;
                return true;
        }
}

int parse_tristate_argument_with_auto(const char *optname, const char *s, int *ret) {
        int r;

        assert(optname);
        assert(s); /* We refuse NULL arg here, since that would be ambiguous on cmdline: for
                    * --enable-a[=BOOL], --enable-a is intuitively interpreted as true rather than "auto"
                    * (parse_boolean_argument() does exactly that). IOW, tristate options should require
                    * arguments. */

        r = parse_tristate_full(s, "auto", ret);
        if (r < 0)
                return log_error_errno(r, "Failed to parse tristate argument to '%s': %s", optname, s);

        return 0;
}

int parse_json_argument(const char *s, sd_json_format_flags_t *ret) {
        assert(s);
        assert(ret);

        if (streq(s, "pretty"))
                *ret = SD_JSON_FORMAT_PRETTY|SD_JSON_FORMAT_COLOR_AUTO;
        else if (streq(s, "short"))
                *ret = SD_JSON_FORMAT_NEWLINE;
        else if (streq(s, "off"))
                *ret = SD_JSON_FORMAT_OFF;
        else if (streq(s, "help")) {
                puts("pretty\n"
                     "short\n"
                     "off");
                return 0; /* 0 means → we showed a brief help, exit now */
        } else
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown argument to --json= switch: %s", s);

        return 1; /* 1 means → properly parsed */
}

int parse_path_argument(const char *path, bool suppress_root, char **arg) {
        char *p;
        int r;

        assert(arg);

        /*
         * This function is intended to be used in command line parsers, to handle paths that are passed
         * in. It makes the path absolute, and reduces it to NULL if omitted or root (the latter optionally).
         *
         * NOTE THAT THIS WILL FREE THE PREVIOUS ARGUMENT POINTER ON SUCCESS!
         * Hence, do not pass in uninitialized pointers.
         */

        if (isempty(path)) {
                *arg = mfree(*arg);
                return 0;
        }

        r = path_make_absolute_cwd(path, &p);
        if (r < 0)
                return log_error_errno(r, "Failed to parse path \"%s\" and make it absolute: %m", path);

        path_simplify(p);
        if (suppress_root && empty_or_root(p))
                p = mfree(p);

        return free_and_replace(*arg, p);
}

int parse_signal_argument(const char *s, int *ret) {
        int r;

        assert(s);
        assert(ret);

        if (streq(s, "help"))
                return DUMP_STRING_TABLE(signal, int, _NSIG);

        if (streq(s, "list")) {
                _cleanup_(table_unrefp) Table *table = NULL;

                table = table_new("signal", "name");
                if (!table)
                        return log_oom();

                for (int i = 1; i < _NSIG; i++) {
                        r = table_add_many(
                                        table,
                                        TABLE_INT, i,
                                        TABLE_SIGNAL, i);
                        if (r < 0)
                                return table_log_add_error(r);
                }

                return table_print_or_warn(table);
        }

        r = signal_from_string(s);
        if (r < 0)
                return log_error_errno(r, "Failed to parse signal string \"%s\".", s);

        *ret = r;
        return 1; /* work to do */
}

int parse_machine_argument(const char *s, const char **ret_host, BusTransport *ret_transport) {
        int r;

        assert(s);
        assert(ret_host);

        r = machine_spec_valid(s);
        if (r < 0)
                return log_error_errno(r, "Failed to validate --machine= argument '%s': %m", s);
        if (r == 0)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid --machine= specified: %s", s);

        *ret_host = s;

        if (ret_transport)
                *ret_transport = BUS_TRANSPORT_MACHINE;

        return 0;
}

int parse_background_argument(const char *s, char **arg) {
        if (!isempty(s) && !looks_like_ansi_color_code(s))
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid --background= argument: %s", s);

        return free_and_strdup_warn(arg, s);
}