#include <u.h>#include <libc.h>#include <bio.h> /* *  for the lock routines in libsys.c */typedef struct Mlock	Mlock;struct Mlock {	int	fd;	int	pid;	char	name[Pathlen];}; /* *  from config.c */extern char *MAILROOT;	/* root of mail system */extern char *SPOOL;	/* spool directory; for spam ctl */extern char *UPASLOG;	/* log directory */extern char *UPASLIB;	/* upas library directory */extern char *UPASBIN;	/* upas binary directory */extern char *UPASTMP;	/* temporary directory */extern char *SHELL;	/* path name of shell */ enum {	Mboxmode	= 0622,}; /* *  files in libsys.c */char	*sysname_read(void);char	*alt_sysname_read(void);char	*domainname_read(void);char	**sysnames_read(void);char	*getlog(void);char	*thedate(void);Biobuf	*sysopen(char*, char*, ulong);int	sysopentty(void);int	sysclose(Biobuf*);int	sysmkdir(char*, ulong);Mlock	*syslock(char *);void	sysunlock(Mlock *);void	syslockrefresh(Mlock *);int	sysrename(char*, char*);int	sysexist(char*);int	syskill(int);int	syskillpg(int);Mlock	*trylock(char *);void	pipesig(int*);void	pipesigoff(void);int	holdon(void);void	holdoff(int);int	syscreatelocked(char*, int, int);int	sysopenlocked(char*, int);int	sysunlockfile(int);int	sysfiles(void);int 	become(char**, char*);int	sysdetach(void);char	*username(char*);int	creatembox(char*, char*);int	createfolder(char*, char*);