/*
 * Public Domain Bourne/Korn shell
 */

#include "config.h"	/* system and option configuration info */

# define	ARGS(args)	args	/* prototype declaration */

#ifdef __GNUC__
# define UNUSED(x) x __attribute__((__unused__))
#else
# define UNUSED(x) x
#endif

/* Start of common headers */

#include <stdio.h>
#include <sys/types.h>
#include <setjmp.h>
#ifdef HAVE_STDDEF_H
# include <stddef.h>
#endif

#include <stdlib.h>
#include <unistd.h>

#ifndef timerclear
#define timerclear(tvp) do { (tvp)->tv_sec = (tvp)->tv_usec = 0; } while (0)
#endif
#ifndef timeradd
#define timeradd(tvp, uvp, vvp)						\
	do {								\
		(vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;		\
		(vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;	\
		if ((vvp)->tv_usec >= 1000000) {			\
			(vvp)->tv_sec++;				\
			(vvp)->tv_usec -= 1000000;			\
		}							\
	} while (0)
#endif
#ifndef timersub
#define timersub(tvp, uvp, vvp)						\
	do {								\
		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
		if ((vvp)->tv_usec < 0) {				\
			(vvp)->tv_sec--;				\
			(vvp)->tv_usec += 1000000;			\
		}							\
	} while (0)
#endif

# include <string.h>

#ifdef HAVE_MEMORY_H
# include <memory.h>
#endif

#ifndef SIZE_MAX
#ifdef SIZE_T_MAX
#define SIZE_MAX	SIZE_T_MAX
#else
#define SIZE_MAX	((size_t)-1)
#endif
#endif

#include <stdarg.h>
#define SH_VA_START(va, argn) va_start(va, argn)

#include <errno.h>
extern int errno;

#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#else
# include <sys/file.h>
#endif /* HAVE_FCNTL_H */
#ifndef O_ACCMODE
# define O_ACCMODE	(O_RDONLY|O_WRONLY|O_RDWR)
#endif /* !O_ACCMODE */

#ifndef F_OK 	/* access() arguments */
# define F_OK 0
# define X_OK 1
# define W_OK 2
# define R_OK 4
#endif /* !F_OK */

#ifndef SEEK_SET
# ifdef L_SET
#  define SEEK_SET L_SET
#  define SEEK_CUR L_INCR
#  define SEEK_END L_XTND
# else /* L_SET */
#  define SEEK_SET 0
#  define SEEK_CUR 1
#  define SEEK_END 2
# endif /* L_SET */
#endif /* !SEEK_SET */

/* Some machines (eg, FreeBSD 1.1.5) define CLK_TCK in limits.h
 * (ksh_limval.h assumes limits has been included, if available)
 */
#ifdef HAVE_LIMITS_H
# include <limits.h>
#endif /* HAVE_LIMITS_H */

#include <signal.h>
#ifdef	NSIG
# define SIGNALS	NSIG
#else
# ifdef	_MINIX
#  define SIGNALS	(_NSIG+1) /* _NSIG is # of signals used, excluding 0. */
# else
#  ifdef _SIGMAX	/* QNX */
#   define SIGNALS	_SIGMAX
#  else /* _SIGMAX */
#   define SIGNALS	32
#  endif /* _SIGMAX */
# endif	/* _MINIX */
#endif	/* NSIG */
#ifndef SIGCHLD
# define SIGCHLD SIGCLD
#endif
/* struct sigaction.sa_flags is set to KSH_SA_FLAGS.  Used to ensure
 * system calls are interrupted
 */
#ifdef SA_INTERRUPT
# define KSH_SA_FLAGS	SA_INTERRUPT
#else /* SA_INTERRUPT */
# define KSH_SA_FLAGS	0
#endif /* SA_INTERRUPT */

typedef	RETSIGTYPE (*handler_t) ARGS((int));	/* signal handler */

#ifdef HAVE_PATHS_H
# include <paths.h>
#endif /* HAVE_PATHS_H */
#ifdef _PATH_DEFPATH
# define DEFAULT__PATH _PATH_DEFPATH
#else /* _PATH_DEFPATH */
# define DEFAULT__PATH DEFAULT_PATH
#endif /* _PATH_DEFPATH */

#ifndef offsetof
# define offsetof(type,id) ((size_t)&((type*)NULL)->id)
#endif

#ifndef HAVE_KILLPG
# define killpg(p, s)	kill(-(p), (s))
#endif /* !HAVE_KILLPG */

/* Special cases for execve(2) */
#ifdef OS2
extern int ksh_execve(char *cmd, char **args, char **env, int flags);
#else /* OS2 */
# if defined(OS_ISC) && defined(_POSIX_SOURCE)
/* Kludge for ISC 3.2 (and other versions?) so programs will run correctly.  */
#  define ksh_execve(p, av, ev, flags) \
				do { \
					__setostype(0); \
					execve(p, av, ev); \
					__setostype(1); \
				} while (0)
# else /* OS_ISC && _POSIX */
#  define ksh_execve(p, av, ev, flags)	execve(p, av, ev)
# endif /* OS_ISC && _POSIX */
#endif /* OS2 */

/* this is a hang-over from older versions of the os2 port */
#define ksh_dupbase(fd, base) fcntl(fd, F_DUPFD, base)

#define ksh_siglongjmp(env,v)	siglongjmp((env), (v))
#define ksh_jmp_buf		sigjmp_buf

#ifndef HAVE_DUP2
extern int dup2 ARGS((int, int));
#endif /* !HAVE_DUP2 */

/* end of common headers */

/* Stop gcc and lint from complaining about possibly uninitialized variables */
#if defined(__GNUC__) || defined(lint)
# define UNINITIALIZED(var)	var = 0
#else
# define UNINITIALIZED(var)	var
#endif /* GNUC || lint */

/* some useful #defines */
#ifdef EXTERN
# define I__(i) = i
#else
# define I__(i)
# define EXTERN extern
# define EXTERN_DEFINED
#endif

#ifndef EXECSHELL
/* shell to exec scripts (see also $SHELL initialization in main.c) */
# ifdef OS2
#  define EXECSHELL	(inDOS() ? "c:\\command.com" : "c:\\os2\\cmd.exe")
#  define EXECSHELL_STR	(inDOS() ? "COMSPEC" : "OS2_SHELL")
# else /* OS2 */
#  define EXECSHELL	"/bin/sh"
#  define EXECSHELL_STR	"EXECSHELL"
# endif /* OS2 */
#endif

/* ISABSPATH() means path is fully and completely specified,
 * ISROOTEDPATH() means a .. as the first component is a no-op,
 * ISRELPATH() means $PWD can be tacked on to get an absolute path.
 *
 * OS		Path		ISABSPATH	ISROOTEDPATH	ISRELPATH
 * unix		/foo		yes		yes		no
 * unix		foo		no		no		yes
 * unix		../foo		no		no		yes
 * os2+cyg	a:/foo		yes		yes		no
 * os2+cyg	a:foo		no		no		no
 * os2+cyg	/foo		no		yes		no
 * os2+cyg	foo		no		no		yes
 * os2+cyg	../foo		no		no		yes
 * cyg 		//foo		yes		yes		no
 */
# define PATHSEP        ':'
# define DIRSEP         '/'
# define DIRSEPSTR      "/"
# define ISDIRSEP(c)    ((c) == '/')
#ifdef __CYGWIN__
#  define ISABSPATH(s) \
       (((s)[0] && (s)[1] == ':' && ISDIRSEP((s)[2])) || ISDIRSEP((s)[0]))
#  define ISRELPATH(s) (!(s)[0] || ((s)[1] != ':' && !ISDIRSEP((s)[0])))
#else /* __CYGWIN__ */
# define ISABSPATH(s)	ISDIRSEP((s)[0])
# define ISRELPATH(s)	(!ISABSPATH(s))
#endif /* __CYGWIN__ */
# define ISROOTEDPATH(s) ISABSPATH(s)
# define FILECHCONV(c)	c
# define FILECMP(s1, s2) strcmp(s1, s2)
# define FILENCMP(s1, s2, n) strncmp(s1, s2, n)
# define ksh_strchr_dirsep(p)   strchr(p, DIRSEP)
# define ksh_strrchr_dirsep(p)  strrchr(p, DIRSEP)

typedef int bool_t;
#define	FALSE	0
#define	TRUE	1

#define	NELEM(a) (sizeof(a) / sizeof((a)[0]))
#define	sizeofN(type, n) (sizeof(type) * (n))
#define	BIT(i)	(1<<(i))	/* define bit in flag */

/* Table flag type - needs > 16 and < 32 bits */
typedef int32_t Tflag;

#define	NUFILE	10		/* Number of user-accessible files */
#define	FDBASE	10		/* First file usable by Shell */

/* you're not going to run setuid shell scripts, are you? */
#define	eaccess(path, mode)	access(path, mode)

/* Make MAGIC a char that might be printed to make bugs more obvious, but
 * not a char that is used often.  Also, can't use the high bit as it causes
 * portability problems (calling strchr(x, 0x80|'x') is error prone).
 */
#define	MAGIC		(7)/* prefix for *?[!{,} during expand */
#define ISMAGIC(c)	((unsigned char)(c) == MAGIC)
#define	NOT		'!'	/* might use ^ (ie, [!...] vs [^..]) */

#define	LINE	1024		/* input line size */
#define	PATH	1024		/* pathname size (todo: PATH_MAX/pathconf()) */
#define ARRAYMAX 1023		/* max array index */

EXTERN	const char *poshname;	/* $0 */
EXTERN	pid_t	kshpid;		/* $$, shell pid */
EXTERN	pid_t	procpid;	/* pid of executing process */
EXTERN	uid_t	ksheuid;	/* effective uid of shell */
EXTERN	int	exstat;		/* exit status */
EXTERN	int	subst_exstat;	/* exit status of last $(..)/`..` */
EXTERN	const char *safe_prompt; /* safe prompt if PS1 substitution fails */


/*
 * Evil hack for const correctness due to API brokenness
 */
union mksh_cchack {
	char *rw;
	const char *ro;
};
union mksh_ccphack {
	char **rw;
	const char **ro;
};

/*
 * simple grouping allocator
 */

/* 1. internal structure */
struct lalloc {
	struct lalloc *next;
};

/* 2. sizes */
#define ALLOC_ITEM	struct lalloc
#define ALLOC_SIZE	(sizeof(ALLOC_ITEM))

/* 3. group structure (only the same for lalloc.c) */
typedef struct lalloc Area;


EXTERN Area aperm;		/* permanent object space */
#define APERM	&aperm
#define ATEMP	&e->area

/*
 * parsing & execution environment
 */
extern struct env {
	ALLOC_ITEM __alloc_i;	/* internal, do not touch */
	Area area;		/* temporary allocation area */
	struct env *oenv;	/* link to previous environment */
	struct block *loc;	/* local variables and functions */
	short *savefd;		/* original redirected fds */
	struct temp *temps;	/* temp files */
	sigjmp_buf jbuf;	/* long jump back to env creator */
	short type;		/* environment type - see below */
	short flags;		/* EF_* */
} *e;

/* struct env.type values */
#define E_NONE	0	/* dummy environment */
#define E_PARSE	1	/* parsing command # */
#define E_FUNC	2	/* executing function # */
#define E_INCL	3	/* including a file via . # */
#define E_EXEC	4	/* executing command tree */
#define E_LOOP	5	/* executing for/while # */
#define E_ERRH	6	/* general error handler # */
/* # indicates env has valid jbuf (see unwind()) */

/* struct env.flag values */
#define EF_FUNC_PARSE	BIT(0)	/* function being parsed */
#define EF_BRKCONT_PASS	BIT(1)	/* set if E_LOOP must pass break/continue on */
#define EF_FAKE_SIGDIE	BIT(2)	/* hack to get info from unwind to quitenv */

/* Do breaks/continues stop at env type e? */
#define STOP_BRKCONT(t)	((t) == E_NONE || (t) == E_PARSE \
			 || (t) == E_FUNC || (t) == E_INCL)
/* Do returns stop at env type e? */
#define STOP_RETURN(t)	((t) == E_FUNC || (t) == E_INCL)

/* values for siglongjmp(e->jbuf, 0) */
#define LRETURN	1	/* return statement */
#define LEXIT	2	/* exit statement */
#define LERROR	3	/* errorf() called */
#define LLEAVE	4	/* untrappable exit/error */
#define LINTR	5	/* ^C noticed */
#define LBREAK	6	/* break statement */
#define LCONTIN	7	/* continue statement */
#define LSHELL	8	/* return to interactive shell() */
#define LAEXPR	9	/* error in arithmetic expression */

/* option processing */
#define OF_CMDLINE	0x01	/* command line */
#define OF_SET		0x02	/* set builtin */
#define OF_SPECIAL	0x04	/* a special variable changing */
#define OF_INTERNAL	0x08	/* set internally by shell */
#define OF_ANY		(OF_CMDLINE | OF_SET | OF_SPECIAL | OF_INTERNAL)

struct posh_option {
    const char	*name;	/* long name of option */
    char	c;	/* character flag (if any) */
    short	flags;	/* OF_* */
};
extern const struct posh_option options[];

/*
 * flags (the order of these enums MUST match the order in misc.c(options[]))
 */
enum sh_flag {
	FEXPORT = 0,	/* -a: export all */
#ifdef BRACE_EXPAND
	FBRACEEXPAND,	/* enable {} globbing */
#endif
	FCOMMAND,	/* -c: (invocation) execute specified command */
#ifdef EMACS
	FEMACS,		/* emacs command editing */
#endif
	FERREXIT,	/* -e: quit on error */
#ifdef EMACS
	FGMACS,		/* gmacs command editing */
#endif
	FIGNOREEOF,	/* eof does not exit */
	FTALKING,	/* -i: interactive */
	FLOGIN,		/* -l: a login shell */
	FMONITOR,	/* -m: job control monitoring */
	FNOCLOBBER,	/* -C: don't overwrite existing files */
	FNOEXEC,	/* -n: don't execute any commands */
	FNOGLOB,	/* -f: don't do file globbing */
	FNOHUP,		/* -H: don't kill running jobs when login shell exits */
	FNOLOG,		/* don't save functions in history (ignored) */
#ifdef	JOBS
	FNOTIFY,	/* -b: asynchronous job completion notification */
#endif
	FNOUNSET,	/* -u: using an unset var is an error */
	FPRIVILEGED,	/* -p: use suid_profile */
	FSTDIN,		/* -s: (invocation) parse stdin */
#ifdef SILLY_FEATURES
	FTRACKALL,	/* -h: create tracked aliases for all commands */
#endif /* SILLY_FEATURES */
	FVERBOSE,	/* -v: echo input */
#ifdef VI
	FVI,		/* vi command editing */
	FVIRAW,		/* always read in raw mode (ignored) */
	FVISHOW8,	/* display chars with 8th bit set as is (versus M-) */
	FVITABCOMPLETE,	/* enable tab as file name completion char */
	FVIESCCOMPLETE,	/* enable ESC as file name completion in command mode */
#endif
	FXTRACE,	/* -x: execution trace */
	FTALKING_I,	/* (internal): initial shell was interactive */
	FNFLAGS /* (place holder: how many flags are there) */
};

#define Flag(f)	(shell_flags[(int) (f)])

EXTERN	char shell_flags [FNFLAGS];

EXTERN	char	null [] I__("");	/* null value for variable */

enum temp_type {
    TT_HEREDOC_EXP,	/* expanded heredoc */
    TT_HIST_EDIT	/* temp file used for history editing (fc -e) */
};
typedef enum temp_type Temp_type;
/* temp/heredoc files.  The file is removed when the struct is freed. */
struct temp {
	struct temp	*next;
	struct shf	*shf;
	int		pid;		/* pid of process parsed here-doc */
	Temp_type	type;
	char		*name;
};

/*
 * stdio and our IO routines
 */

#define shl_spare	(&shf_iob[0])	/* for c_read()/c_print() */
#define shl_stdout	(&shf_iob[1])
#define shl_out		(&shf_iob[2])
EXTERN int shl_stdout_ok;

/*
 * trap handlers
 */
typedef struct trap {
	int	signal;		/* signal number */
	const char *name;	/* short name */
	const char *mess;	/* descriptive name */
	char   *trap;		/* trap command */
	int	volatile set;	/* trap pending */
	int	flags;		/* TF_* */
	handler_t cursig;	/* current handler (valid if TF_ORIG_* set) */
	handler_t shtrap;	/* shell signal handler */
} Trap;

/* values for Trap.flags */
#define TF_SHELL_USES	BIT(0)	/* shell uses signal, user can't change */
#define TF_USER_SET	BIT(1)	/* user has (tried to) set trap */
#define TF_ORIG_IGN	BIT(2)	/* original action was SIG_IGN */
#define TF_ORIG_DFL	BIT(3)	/* original action was SIG_DFL */
#define TF_EXEC_IGN	BIT(4)	/* restore SIG_IGN just before exec */
#define TF_EXEC_DFL	BIT(5)	/* restore SIG_DFL just before exec */
#define TF_DFL_INTR	BIT(6)	/* when received, default action is LINTR */
#define TF_TTY_INTR	BIT(7)	/* tty generated signal (see j_waitj) */
#define TF_CHANGED	BIT(8)	/* used by runtrap() to detect trap changes */
#define TF_FATAL	BIT(9)	/* causes termination if not trapped */

/* values for setsig()/setexecsig() flags argument */
#define SS_RESTORE_MASK	0x3	/* how to restore a signal before an exec() */
#define SS_RESTORE_CURR	0	/* leave current handler in place */
#define SS_RESTORE_ORIG	1	/* restore original handler */
#define SS_RESTORE_DFL	2	/* restore to SIG_DFL */
#define SS_RESTORE_IGN	3	/* restore to SIG_IGN */
#define SS_FORCE	BIT(3)	/* set signal even if original signal ignored */
#define SS_USER		BIT(4)	/* user is doing the set (ie, trap command) */
#define SS_SHTRAP	BIT(5)	/* trap for internal use (CHLD,ALRM,WINCH) */

#define SIGEXIT_	0	/* for trap EXIT */

EXTERN	int volatile trap;	/* traps pending? */
EXTERN	int volatile intrsig;	/* pending trap interrupts executing command */
EXTERN	int volatile fatal_trap;/* received a fatal signal */
#ifndef FROM_TRAP_C
/* Kludge to avoid bogus re-declaration of sigtraps[] error on AIX 3.2.5 */
extern	Trap	sigtraps[SIGNALS+1];
#endif /* !FROM_TRAP_C */


#ifdef KSH
/*
 * TMOUT support
 */
/* values for ksh_tmout_state */
enum tmout_enum {
		TMOUT_EXECUTING	= 0,	/* executing commands */
		TMOUT_READING,		/* waiting for input */
		TMOUT_LEAVING		/* have timed out */
	};
EXTERN unsigned int ksh_tmout;
EXTERN enum tmout_enum ksh_tmout_state I__(TMOUT_EXECUTING);
#endif /* KSH */


/* For "You have stopped jobs" message */
EXTERN int really_exit;


/*
 * fast character classes
 */
#define	C_LEX1	 BIT(2)		/* \0 \t\n|&;<>() */
#define	C_VAR1	 BIT(3)		/* *@#!$-? */
#define	C_IFSWS	 BIT(4)		/* \t \n (IFS white space) */
#define	C_SUBOP1 BIT(5)		/* "=-+?" */
#define	C_SUBOP2 BIT(6)		/* "#%" */
#define	C_IFS	 BIT(7)		/* $IFS */
#define	C_QUOTE	 BIT(8)		/*  \n\t"#$&'()*;<>?[\`| (needing quoting) */

extern	short ctypes [];

#define	ctype(c, t)	!!(ctypes[(unsigned char)(c)]&(t))

EXTERN int ifs0 I__(' ');	/* for "$*" */


/* Argument parsing for built-in commands and getopts command */

/* Values for Getopt.flags */
#define GF_ERROR	BIT(0)	/* call errorf() if there is an error */
#define GF_PLUSOPT	BIT(1)	/* allow +c as an option */
#define GF_NONAME	BIT(2)	/* don't print argv[0] in errors */

/* Values for Getopt.info */
#define GI_MINUS	BIT(0)	/* an option started with -... */
#define GI_PLUS		BIT(1)	/* an option started with +... */
#define GI_MINUSMINUS	BIT(2)	/* arguments were ended with -- */

typedef struct {
	int		optind;
	int		uoptind;/* what user sees in $OPTIND */
	char		*optarg;
	int		flags;	/* see GF_* */
	int		info;	/* see GI_* */
	unsigned int	p;	/* 0 or index into argv[optind - 1] */
	char		buf[2];	/* for bad option OPTARG value */
} LameGetopt;

EXTERN LameGetopt builtin_opt;	/* for shell builtin commands */
EXTERN LameGetopt user_opt;		/* parsing state for getopts builtin command */


#ifdef KSH
/* This for co-processes */

typedef INT32 Coproc_id; /* something that won't (realisticly) wrap */
struct coproc {
	int	read;		/* pipe from co-process's stdout */
	int	readw;		/* other side of read (saved temporarily) */
	int	write;		/* pipe to co-process's stdin */
	Coproc_id id;		/* id of current output pipe */
	int	njobs;		/* number of live jobs using output pipe */
	void    *job;           /* 0 or job of co-process using input pipe */
};
EXTERN struct coproc coproc;
#endif /* KSH */

/* Used in jobs.c and by coprocess stuff in exec.c */
EXTERN sigset_t		sm_default, sm_sigchld;

/* name of called builtin function (used by error functions) */
EXTERN char	*builtin_argv0;
EXTERN Tflag	builtin_flag;	/* flags of called builtin (SPEC_BI, etc.) */

/* current working directory, and size of memory allocated for same */
EXTERN char	*current_wd;
EXTERN int	current_wd_size;

#ifdef EDIT
/* Minimium required space to work with on a line - if the prompt leaves less
 * space than this on a line, the prompt is truncated.
 */
# define MIN_EDIT_SPACE	7
/* Minimium allowed value for x_cols: 2 for prompt, 3 for " < " at end of line
 */
# define MIN_COLS	(2 + MIN_EDIT_SPACE + 3)
EXTERN	int	x_cols I__(80);	/* tty columns */
#else
# define x_cols 80		/* for pr_menu(exec.c) */
#endif


/* These to avoid bracket matching problems */
#define OPAREN	'('
#define CPAREN	')'
#define OBRACK	'['
#define CBRACK	']'
#define OBRACE	'{'
#define CBRACE	'}'

/* Determine the location of the system (common) profile */
#ifndef KSH_SYSTEM_PROFILE
# ifdef __NeXT
#  define KSH_SYSTEM_PROFILE "/etc/profile.std"
# else /* __NeXT */
#  define KSH_SYSTEM_PROFILE "/etc/profile"
# endif /* __NeXT */
#endif /* KSH_SYSTEM_PROFILE */

/* Used by v_evaluate() and setstr() to control action when error occurs */
#define KSH_UNWIND_ERROR	0	/* unwind the stack (longjmp) */
#define KSH_RETURN_ERROR	1	/* return 1/0 for success/failure */

#include "shf.h"
#include "table.h"
#include "tree.h"
#include "expand.h"
#include "lex.h"
#include "proto.h"

/* user and system time of last j_waitjed job */
EXTERN struct timeval j_usrtime, j_systime;


#define alloc(n, ap)    aresize(NULL, (n), (ap))

/* be sure not to interfere with anyone else's idea about EXTERN */
#ifdef EXTERN_DEFINED
# undef EXTERN_DEFINED
# undef EXTERN
#endif
#undef I__
