extern const uschar *config_filename; /* Configuration file name */
extern gid_t config_gid; /* Additional group owner */
extern int config_lineno; /* Line number */
-extern uschar *config_main_filelist; /* List of possible config files */
+extern const uschar *config_main_filelist; /* List of possible config files */
extern uschar *config_main_filename; /* File name actually used */
extern uschar *config_main_directory; /* Directory where the main config file was found */
extern uid_t config_uid; /* Additional owner */
extern int filter_n[FILTER_VARIABLE_COUNT]; /* filter variables */
extern int filter_sn[FILTER_VARIABLE_COUNT]; /* variables set by system filter */
extern int filter_test; /* Filter test type */
-extern uschar *filter_test_sfile; /* System filter test file */
-extern uschar *filter_test_ufile; /* User filter test file */
+extern const uschar *filter_test_sfile;/* System filter test file */
+extern const uschar *filter_test_ufile;/* User filter test file */
extern uschar *filter_thisaddress; /* For address looping */
extern int finduser_retries; /* Retry count for getpwnam() */
extern uid_t fixed_never_users[]; /* Can't be overridden */
const extern pcre2_code *regex_UTF8; /* For recognizing SMTPUTF8 settings */
#endif
extern uschar message_subdir[]; /* Subdirectory for messages */
-extern uschar *message_reference; /* Reference for error messages */
+extern const uschar *message_reference;/* Reference for error messages */
/* MIME ACL expandables */
#ifdef WITH_CONTENT_SCAN
extern uschar *originator_name; /* Full name of same */
extern uid_t originator_uid; /* Uid of ditto */
extern uschar *override_local_interfaces; /* Value of -oX argument */
-extern uschar *override_pid_file_path; /* Value of -oP argument */
+extern const uschar *override_pid_file_path; /* Value of -oP argument */
extern BOOL panic_coredump; /* SEGV rather than exit, on LOG_PANIC_DIE */
extern pcre2_general_context * pcre_gen_ctx; /* pcre memory management */
extern pcre2_compile_context * pcre_mlc_cmp_ctx;
extern uschar *percent_hack_domains; /* Local domains for which '% operates */
-extern uschar *pid_file_path; /* For writing daemon pids */
+extern const uschar *pid_file_path; /* For writing daemon pids */
#ifndef DISABLE_PIPE_CONNECT
extern uschar *pipe_connect_advertise_hosts; /* for banner/EHLO pipelining */
#endif
extern int sending_port; /* Port of outgoing interface */
extern SIGNAL_BOOL sigalrm_seen; /* Flag for sigalrm_handler */
extern const uschar *sigalarm_setter; /* For debug, set to callpoint of alarm() */
-extern uschar **sighup_argv; /* Args for re-execing after SIGHUP */
+extern const uschar **sighup_argv; /* Args for re-execing after SIGHUP */
extern int slow_lookup_log; /* Log DNS lookups taking longer than N millisecs */
extern int smtp_accept_count; /* Count of connections */
extern BOOL smtp_accept_keepalive; /* Set keepalive on incoming */
extern BOOL syslog_duplication; /* FALSE => no duplicate logging */
extern int syslog_facility; /* As defined by Syslog.h */
extern BOOL syslog_pid; /* TRUE if PID on syslogs */
-extern uschar *syslog_processname; /* 'ident' param to openlog() */
+extern const uschar *syslog_processname; /* 'ident' param to openlog() */
extern BOOL syslog_timestamp; /* TRUE if time on syslogs */
extern uschar *system_filter; /* Name of system filter file */