/* parse.h -- Hui Dai September 2003 for cs170 */

#ifndef _PARSE_H_
#define _PARSE_H_

#define LINEMAX 2048  /* expected maximum characters per input line */
#define PARSEDLINE (LINEMAX*2)

/* the following are return codes for the parse() function */
#define SUCCESS        0    /* there are no mistakes */
#define EOF_REACHED   -1    /* AKA ctrl-D */
#define EMPTYLINE     -2    /* no non-white space detected in input */
#define BADSYMBOL     -4    /* unrecognized special symbols */
#define BADPLACEMENT  -8    /* the line does not parse correctly */
#define MALLOCFAILED  -16   /* this should not happen */

/* command structure */
typedef struct command_struct
{
    struct command_struct * prevCmd;
    struct command_struct * nextCmd;
    char * file;
    char ** argv;
    char * in_redir;
    char * out_redir;
    int appending;      /* flag, non-zero = append, zero = truncate */
    int background;     /* whether the line terminates with an & */
} CMD;

int parse(CMD **);    /* returns an error code, CMD ** outParameter */
int cmd_free(CMD *);

#endif