/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __SUBCMD_RUN_COMMAND_H
#define __SUBCMD_RUN_COMMAND_H

#include <unistd.h>

enum {
        ERR_RUN_COMMAND_FORK = 10000,
        ERR_RUN_COMMAND_EXEC,
        ERR_RUN_COMMAND_PIPE,
        ERR_RUN_COMMAND_WAITPID,
        ERR_RUN_COMMAND_WAITPID_WRONG_PID,
        ERR_RUN_COMMAND_WAITPID_SIGNAL,
        ERR_RUN_COMMAND_WAITPID_NOEXIT,
};
#define IS_RUN_COMMAND_ERR(x) (-(x) >= ERR_RUN_COMMAND_FORK)

struct child_process {
        const char **argv;
        pid_t pid;
        /*
         * Using .in, .out, .err:
         * - Specify 0 for no redirections (child inherits stdin, stdout,
         *   stderr from parent).
         * - Specify -1 to have a pipe allocated as follows:
         *     .in: returns the writable pipe end; parent writes to it,
         *          the readable pipe end becomes child's stdin
         *     .out, .err: returns the readable pipe end; parent reads from
         *          it, the writable pipe end becomes child's stdout/stderr
         *   The caller of start_command() must close the returned FDs
         *   after it has completed reading from/writing to it!
         * - Specify > 0 to set a channel to a particular FD as follows:
         *     .in: a readable FD, becomes child's stdin
         *     .out: a writable FD, becomes child's stdout/stderr
         *     .err > 0 not supported
         *   The specified FD is closed by start_command(), even in case
         *   of errors!
         */
        int in;
        int out;
        int err;
        const char *dir;
        const char *const *env;
        int finish_result;
        unsigned no_stdin:1;
        unsigned no_stdout:1;
        unsigned no_stderr:1;
        unsigned exec_cmd:1; /* if this is to be external sub-command */
        unsigned stdout_to_stderr:1;
        unsigned finished:1;
        void (*preexec_cb)(void);
         /* If set, call function in child rather than doing an exec. */
        int (*no_exec_cmd)(struct child_process *process);
};

int start_command(struct child_process *);
int check_if_command_finished(struct child_process *);
int finish_command(struct child_process *);
int run_command(struct child_process *);

#define RUN_COMMAND_NO_STDIN 1
#define RUN_EXEC_CMD         2  /*If this is to be external sub-command */
#define RUN_COMMAND_STDOUT_TO_STDERR 4
int run_command_v_opt(const char **argv, int opt);

#endif /* __SUBCMD_RUN_COMMAND_H */