/* Based (very loosely) on Ostermann's headstart for the shell project
* Modified by Kyle Wheeler
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>		       /* for stat() */
#include <ctype.h>		       /* for isdigit and isalpha */
#include <errno.h>
#include <fcntl.h>		       /* for open() */
#include <limits.h>		       /* for stroul() and PATH_MAX */
#include "number.h"

#ifdef HAVE_LIBREADLINE
# if defined(HAVE_READLINE_READLINE_H)
#  include <readline/readline.h>
# elif defined(HAVE_READLINE_H)
#  include <readline.h>
# else /* !defined(HAVE_READLINE_H) */
extern char *readline();
# endif	/* !defined(HAVE_READLINE_H) */
/*@null@*/
char *cmdline = NULL;
#else /* !defined(HAVE_READLINE_READLINE_H) */
/* no readline */
#endif /* HAVE_LIBREADLINE */

#ifdef HAVE_READLINE_HISTORY
# if defined(HAVE_READLINE_HISTORY_H)
#  include <readline/history.h>
# elif defined(HAVE_HISTORY_H)
#  include <history.h>
# else /* ! defined(HAVE_HISTORY_H) */
extern void add_history();
extern int write_history();
extern int read_history();
extern int history_truncate_file(char *, int);
# endif	/* defined(HAVE_READLINE_HISTORY_H) */
/* no history */
#endif /* HAVE_READLINE_HISTORY */

#include "calculator.h"
#include "conversion.h"
#ifdef HAVE_CONFIG_H /* auto-tool build */
# include "parser.h"
#else
# include "y.tab.h"
#endif
#include "variables.h"
#include "help.h"
#include "files.h"
#include "historyManager.h"
#include "list.h"
#include "isconst.h"
#ifdef MEMWATCH
#include "memwatch.h"
#endif

#define TRUEFALSE (! strcmp(value,"yes") || ! strcmp(value,"true") || ! strcmp(value,"1"))
#define BIG_STRING 4096

static int read_prefs(char *filename);
static int read_preload(char *filename);

/*
 * These are declared here because they're not in any header files.
 * yyparse() is declared with an empty argument list so that it is
 * compatible with the generated C code from yacc/bison.
 * This part is taken from http://www.bgw.org/tutorials/programming/c/lex_yacc/main.c
 */
extern int yyparse(void);
extern int yy_scan_string(const char *);

#ifdef HAVE_LIBREADLINE
/*@null@*/
static List tc_options = NULL;

/*@null@*/
char *tc_generator(const char *text, int state)
{				       /*{{{ */
    char *ret = getHeadOfList(tc_options);

    if (ret) {
	return ret;
    } else
	return NULL;
}				       /*}}} */

/*@null@*/
char *tc_rounding(const char *text, int state)
{				       /*{{{ */
    static unsigned int i = 0;
    char *rounding[] = { "none", "simple", "sig_fig", 0 };
    if (state == 0) {
	i = 0;
    }
    while (rounding[i] != NULL) {
	if (strncmp(text, rounding[i], strlen(text)) == 0) {
	    return strdup(rounding[i++]);
	}
	i++;
    }
    return NULL;
}				       /*}}} */

/*@null@*/
char *tc_engineering(const char *text, int state)
{				       /*{{{ */
    static unsigned int i = 0;
    char *engineering[] = { "always", "never", "auto", "automatic", 0 };
    if (state == 0) {
	i = 0;
    }
    while (engineering[i] != NULL) {
	if (strncmp(text, engineering[i], strlen(text)) == 0) {
	    return strdup(engineering[i++]);
	}
	i++;
    }
    return NULL;
}				       /*}}} */

#define COMPLETE(strs) do { \
    int compareword = 0; \
    int comparechar = 0; \
    int textcurs = 0; \
    while (strs[compareword] != NULL) { \
	if (text[textcurs] == 0) { /* add to the list of possibilities */ \
	    addToList(&tc_options, strdup(strs[compareword])); \
	    textcurs = 0; \
	    comparechar = 0; \
	    compareword++; \
	} else if (text[textcurs] == strs[compareword][comparechar]) { \
	    textcurs++; \
	    comparechar++; \
	} else { /* not a possibility: next! */ \
	    textcurs = 0; \
	    compareword++; \
	    comparechar = 0; \
	} \
    } \
} while (0)
#define COMPLETE2(strs) do { \
    int compareword = 0; \
    int comparechar = 0; \
    int textcurs = 0; \
    while (strs[compareword].label != NULL) { \
	if (text[textcurs] == 0) { /* add to the list of possibilities */ \
	    addToList(&tc_options, strdup(strs[compareword].label)); \
	    textcurs = 0; \
	    comparechar = 0; \
	    compareword++; \
	} else if (text[textcurs] == strs[compareword].label[comparechar]) { \
	    textcurs++; \
	    comparechar++; \
	} else { /* not a possibility: next! */ \
	    textcurs = 0; \
	    compareword++; \
	    comparechar = 0; \
	} \
    } \
} while (0)

char **wcalc_completion(const char *text, int start, int end)
{				       /*{{{ */
    /*extern const char *commands[];*/
    extern const char *qcommands[];
    extern const char *funcs[];
    char **variables;
    char **retvals = NULL;

    //printf("\ncompleting: %s\n", text);
    if ('\\' == rl_line_buffer[0]) {
	if (NULL == strchr(rl_line_buffer, ' ') &&
	    NULL == strchr(rl_line_buffer, '\t')) {
	    COMPLETE(qcommands);
	} else if (strncmp("\\explain", rl_line_buffer, 8) == 0) {
	    int i = 8;

	    while (isspace(rl_line_buffer[i]))
		++i;
	    if (i == start) {
		COMPLETE(qcommands);
		COMPLETE2(consts);
		COMPLETE(funcs);
		variables = listvarnames();
		COMPLETE(variables);
		free(variables);
	    }
	} else if (strncmp("\\open", rl_line_buffer, 5) == 0 ||
		   strncmp("\\save", rl_line_buffer, 5) == 0) {
	    int i = 5;

	    while (isspace(rl_line_buffer[i]))
		++i;
	    if (i == start) {
		retvals =
		    rl_completion_matches(text,
					  rl_filename_completion_function);
		return retvals;
	    }
	} else
	    if ((strncmp("\\rou", rl_line_buffer, 4) == 0 &&
		 isspace(rl_line_buffer[4])) ||
		(strncmp("\\round", rl_line_buffer, 6) == 0 &&
		 isspace(rl_line_buffer[6])) ||
		(strncmp("\\rounding", rl_line_buffer, 9) == 0 &&
		 isspace(rl_line_buffer[9]))) {
	    int i = 4;

	    while (!isspace(rl_line_buffer[i]))
		++i;
	    while (isspace(rl_line_buffer[i]))
		++i;
	    if (i == start) {
		retvals = rl_completion_matches(text, tc_rounding);
		return retvals;
	    }
	} else
	    if ((strncmp("\\e", rl_line_buffer, 2) == 0 &&
	         isspace(rl_line_buffer[2])) ||
		(strncmp("\\eng", rl_line_buffer, 4) == 0 &&
		 isspace(rl_line_buffer[4])) ||
		(strncmp("\\engineering", rl_line_buffer, 12) == 0 &&
		 isspace(rl_line_buffer[12]))) {
	    int i = 2;

	    while (!isspace(rl_line_buffer[i]))
		++i;
	    while (isspace(rl_line_buffer[i]))
		++i;
	    if (i == start) {
		retvals = rl_completion_matches(text, tc_engineering);
		return retvals;
	    }
	} else
	    if ((strncmp("\\c", rl_line_buffer, 2) == 0 &&
		 isspace(rl_line_buffer[2])) ||
		(strncmp("\\conv", rl_line_buffer, 5) == 0 &&
		 isspace(rl_line_buffer[5])) ||
		(strncmp("\\convert", rl_line_buffer, 8) == 0 &&
		 isspace(rl_line_buffer[8]))) {
	    int i = 2;
	    /*extern const struct conversion lengths[], areas[], volumes[],
		masses[], speeds[], powers[], forces[], accelerations[];*/
	    extern const struct conversion *conversions[];

	    while (!isspace(rl_line_buffer[i]))
		++i;
	    while (isspace(rl_line_buffer[i]))
		++i;
	    if (i == start) {
		/* complete on ALL units */
		size_t unit, conversion;

		for (conversion = 0; conversions[conversion]; conversion++) {
		    for (unit = 0; conversions[conversion][unit].name; unit++) {
			COMPLETE(conversions[conversion][unit].aka);
		    }
		}
	    } else {
		/* seek past the previous unit... */
		char *unit1 = rl_line_buffer + i;
		char saved_char;
		ssize_t unit_cat;

		while (!isspace(rl_line_buffer[i]))
		    ++i;
		saved_char = rl_line_buffer[i];
		rl_line_buffer[i] = 0;
		unit_cat = identify_unit(unit1);
		rl_line_buffer[i] = saved_char;
		if (unit_cat != -1) {
		    while (isspace(rl_line_buffer[i]))
			++i;
		    if (i == start) {
			size_t unit;

			/* complete on COMPATABLE units */
			for (unit = 0; conversions[unit_cat][unit].name;
			     unit++) {
			    COMPLETE(conversions[unit_cat][unit].aka);
			}
			addToList(&tc_options, strdup("to"));
		    } else if (strncmp(rl_line_buffer + i, "to", 2) == 0 &&
			       isspace(rl_line_buffer[i + 2])) {
			i += 2;
			while (isspace(rl_line_buffer[i]))
			    ++i;
			if (i == start) {
			    size_t unit;

			    /* complete on COMPATABLE units */
			    for (unit = 0; conversions[unit_cat][unit].name;
				 unit++) {
				COMPLETE(conversions[unit_cat][unit].aka);
			    }
			}
		    }
		}
	    }
	}
    } else {
	COMPLETE(qcommands);
	COMPLETE2(consts);
	COMPLETE(funcs);
	variables = listvarnames();
	COMPLETE(variables);
	free(variables);
    }
    rl_attempted_completion_over = 1;  // do not use standard file completion
    rl_completion_entry_function = tc_generator;
    retvals = rl_completion_matches(text, tc_generator);
    return retvals;
}				       /*}}} */
#endif

int main(int argc, char *argv[])
{				       /*{{{ */
    extern int yydebug;
    extern int lines;

#ifdef HAVE_LIBREADLINE
    char *readme = NULL;
#else
    char readme[BIG_STRING];
#endif
    int tty, i;
    short cmdline_input = 0;

    yydebug = 1;		       /* turn on ugly YACC debugging */
    yydebug = 0;		       /* turn off ugly YACC debugging */

    initvar();
    lists_init();

    /* initialize the preferences */
    conf.precision = -1;
    conf.engineering = automatic;
    standard_output = 1;
    conf.picky_variables = 1;
    conf.print_prefixes = 1;
    conf.precision_guard = 1;
    conf.in_thou_delimiter = 0;
    conf.in_dec_delimiter = 0;
    conf.thou_delimiter = ',';
    conf.dec_delimiter = '.';
    conf.print_equal = 1;
    conf.print_ints = 0;
    conf.print_commas = 0;
    conf.verbose = 0;
    conf.c_style_mod = 1;

    init_numbers();
    num_init_set_ui(last_answer, 0);

    /* load the preferences */
    {
	char filename[PATH_MAX];
	int foundflag = 0;

	/* quick check the commandline for a --defaults argument */
	for (i = 1; i < argc; ++i) {
	    if (!strcmp(argv[i], "--defaults")) {
		foundflag = 1;
		break;
	    }
	}

	if (foundflag == 0) {
	    snprintf(filename, PATH_MAX, "%s/.wcalcrc", getenv("HOME"));
	    if (read_prefs(filename)) {
		perror("Writing Preferences");
	    }
	    snprintf(filename, PATH_MAX, "%s/.wcalc_preload", getenv("HOME"));
	    if (read_preload(filename)) {
		perror("Reading Preload File");
	    }
	}
    }

    /* Parse commandline options */
    for (i = 1; i < argc; ++i) {
	if (!strncmp(argv[i], "-P", 2)) {
	    long int argnum;
	    char *endptr;

	    argnum = strtol(&(argv[i][2]), &endptr, 0);
	    if (endptr != NULL && (strlen(endptr) > 0)) {
		fprintf(stderr,
			"-P option requires a valid integer without spaces.\n");
		fflush(stderr);
		num_free(last_answer);
		exit(EXIT_FAILURE);
	    } else {
		conf.precision = (int)argnum;
	    }
	} else if (!strcmp(argv[i], "-E") ||
		   !strcmp(argv[i], "--engineering")) {
	    conf.engineering = always;
	} else if (!strcmp(argv[i], "-EE")) {
	    conf.engineering = never;
	} else if (!strcmp(argv[i], "-H") || !strcmp(argv[i], "--help")) {
	    print_command_help();
	    num_free(last_answer);
	    exit(EXIT_SUCCESS);
	} else if (!strcmp(argv[i], "-v") || !strcmp(argv[i], "--version")) {
	    printf("wcalc "VERSION"\n");
	    num_free(last_answer);
	    exit(EXIT_SUCCESS);
	} else if (!strcmp(argv[i], "-d") || !strcmp(argv[i], "--decimal") ||
		   !strcmp(argv[i], "-dec") || !strcmp(argv[i], "--dec")) {
	    conf.output_format = DECIMAL_FORMAT;
	} else if (!strcmp(argv[i], "-h") || !strcmp(argv[i], "--hexadecimal")
		   || !strcmp(argv[i], "-hex") || !strcmp(argv[i], "--hex")) {
	    conf.output_format = HEXADECIMAL_FORMAT;
	} else if (!strcmp(argv[i], "-o") || !strcmp(argv[i], "--octal") ||
		   !strcmp(argv[i], "-oct") || !strcmp(argv[i], "--oct")) {
	    conf.output_format = OCTAL_FORMAT;
	} else if (!strcmp(argv[i], "-b") || !strcmp(argv[i], "--binary") ||
		   !strcmp(argv[i], "-bin") || !strcmp(argv[i], "--bin")) {
	    conf.output_format = BINARY_FORMAT;
	} else if (!strcmp(argv[i], "-p") || !strcmp(argv[i], "--prefixes")) {
	    conf.print_prefixes = !conf.print_prefixes;
	    /*} else if (!strcmp(argv[i], "-l") || !strcmp(argv[i], "--lenient")) {
	     * conf.picky_variables = 0; */
	} else if (!strcmp(argv[i], "-r") || !strcmp(argv[i], "--radians")) {
	    conf.use_radians = !conf.use_radians;
	} else if (!strcmp(argv[i], "-q") || !strcmp(argv[i], "--quiet")) {
	    conf.print_equal = !conf.print_equal;
	} else if (!strcmp(argv[i], "-c") ||
		   !strcmp(argv[i], "--conservative")) {
	    conf.precision_guard = !conf.precision_guard;
	} else if (!strcmp(argv[i], "-R") || !strcmp(argv[i], "--remember")) {
	    conf.remember_errors = !conf.remember_errors;
	} else if (!strncmp(argv[i], "--round=", 8)) {
	    if (!strcmp(&(argv[i][8]), "no") ||
		!strcmp(&(argv[i][8]), "none")) {
		conf.rounding_indication = NO_ROUNDING_INDICATION;
	    } else if (!strcmp(&(argv[i][8]), "simple")) {
		conf.rounding_indication = SIMPLE_ROUNDING_INDICATION;
	    } else if (!strcmp(&(argv[i][8]), "sig_fig")) {
		conf.rounding_indication = SIG_FIG_ROUNDING_INDICATION;
	    }
	} else if (!strcmp(argv[i], "--round")) {
	    fprintf(stderr,
		    "--round requires an argument (none|simple|sig_fig)\n");
	    exit(EXIT_FAILURE);
	} else if (!strncmp(argv[i], "--idsep=", 7)) {
	    if (strlen(argv[i]) > 8 || strlen(argv[i]) == 7) {
		fprintf(stderr, "--idsep= must have an argument\n");
		exit(EXIT_FAILURE);
	    }
	    if (conf.in_thou_delimiter != argv[i][7] && (conf.in_thou_delimiter != 0 || conf.thou_delimiter != argv[i][7])) {
		conf.in_dec_delimiter = argv[i][7];
	    } else {
		fprintf(stderr,
			"%c cannot be the decimal separator. It is the thousands separator.\n",
			argv[i][7]);
		exit(EXIT_FAILURE);
	    }
	} else if (!strncmp(argv[i], "--dsep=", 7)) {
	    if (strlen(argv[i]) > 8 || strlen(argv[i]) == 7) {
		fprintf(stderr, "--dsep= must have an argument\n");
		exit(EXIT_FAILURE);
	    }
	    if (conf.thou_delimiter != argv[i][7]) {
		conf.dec_delimiter = argv[i][7];
	    } else {
		fprintf(stderr,
			"%c cannot be the decimal separator. It is the thousands separator.\n",
			argv[i][7]);
		exit(EXIT_FAILURE);
	    }
	} else if (!strncmp(argv[i], "--itsep=", 7)) {
	    if (strlen(argv[i]) > 8 || strlen(argv[i]) == 7) {
		fprintf(stderr, "--itsep= must have an argument\n");
		exit(EXIT_FAILURE);
	    }
	    if (conf.in_dec_delimiter != argv[i][7] && (conf.in_dec_delimiter != 0 || conf.dec_delimiter != argv[i][7])) {
		conf.in_thou_delimiter = argv[i][7];
	    } else {
		fprintf(stderr,
			"%c cannot be the thousands separator. It is the decimal separator.\n",
			argv[i][7]);
		exit(EXIT_FAILURE);
	    }
	} else if (!strncmp(argv[i], "--tsep=", 7)) {
	    if (strlen(argv[i]) > 8 || strlen(argv[i]) == 7) {
		fprintf(stderr, "--tsep= must have an argument\n");
		exit(EXIT_FAILURE);
	    }
	    if (conf.dec_delimiter != argv[i][7]) {
		conf.thou_delimiter = argv[i][7];
	    } else {
		fprintf(stderr,
			"%c cannot be the thousands separator. It is the decimal separator.\n",
			argv[i][7]);
		exit(EXIT_FAILURE);
	    }
	} else if (!strncmp(argv[i], "--bits", 6)) {
	    unsigned long int argnum;
	    char *endptr;

	    argnum = strtoul(&(argv[i][6]), &endptr, 0);
	    if (endptr != NULL && (strlen(endptr) > 0)) {
		fprintf(stderr,
			"--bits option requires a valid integer without spaces.\n");
		num_free(last_answer);
		exit(EXIT_FAILURE);
	    } else {
		if (argnum < NUM_PREC_MIN) {
		    fprintf(stderr,"Minimum precision is %lu.\n", (unsigned long)NUM_PREC_MIN);
		} else if (argnum > NUM_PREC_MAX) {
		    fprintf(stderr,"Maximum precision is %lu.\n", (unsigned long)NUM_PREC_MAX);
		} else {
		    num_set_default_prec(argnum);
		}
	    }
	} else if (!strcmp(argv[i], "--ints")) {
	    conf.print_ints = !conf.print_ints;
	} else if (!strcmp(argv[i], "--delim")) {
	    conf.print_commas = !conf.print_commas;
	} else if (!strcmp(argv[i], "--verbose")) {
	    conf.verbose = !conf.verbose;
	} else if (!strcmp(argv[i], "--yydebug")) {
	    yydebug = 1;
	} else if (!strcmp(argv[i], "-n")) {
	    conf.print_equal = 0;
	} else if (!strcmp(argv[i], "--defaults")) {
	    /* ignore this argument */
	} else {
	    extern char *errstring;

	    if (!cmdline_input) {
#ifdef HAVE_READLINE_HISTORY
		char filename[PATH_MAX];

		using_history();
		snprintf(filename, PATH_MAX, "%s/.wcalc_history",
			 getenv("HOME"));
		if (read_history(filename)) {
		    if (errno != ENOENT) {
			perror("Reading History");
		    }
		}
#endif
		cmdline_input = 1;
	    }
	    if (conf.verbose) {
		printf("-> %s\n", argv[i]);
	    }
	    parseme(argv[i]);
	    if (!errstring || (errstring && !strlen(errstring)) ||
		conf.remember_errors) {
		addToHistory(argv[i], last_answer);
	    }
	    if (errstring && strlen(errstring)) {
		fprintf(stderr, "%s", errstring);
		if (errstring[strlen(errstring) - 1] != '\n')
		    fprintf(stderr, "\n");
		free(errstring);
		errstring = NULL;
	    }
	    if (putval("a", last_answer, "previous answer") != 0) {
		fprintf(stderr, "error storing last answer\n");
	    }
	}
    }

    if (! cmdline_input) {
	extern char *errstring;
	char * envinput = getenv("wcalc_input");
	if (envinput) {
#ifdef HAVE_READLINE_HISTORY
	    char filename[PATH_MAX];

	    using_history();
	    snprintf(filename, PATH_MAX, "%s/.wcalc_history",
		    getenv("HOME"));
	    if (read_history(filename)) {
		if (errno != ENOENT) {
		    perror("Reading History");
		}
	    }
#endif
	    cmdline_input = 1;
	    if (conf.verbose) {
		printf("-> %s\n", envinput);
	    }
	    parseme(envinput);
	    if (!errstring || (errstring && !strlen(errstring)) ||
		conf.remember_errors) {
		addToHistory(envinput, last_answer);
	    }
	    if (errstring && strlen(errstring)) {
		fprintf(stderr, "%s", errstring);
		if (errstring[strlen(errstring) - 1] != '\n')
		    fprintf(stderr, "\n");
		free(errstring);
		errstring = NULL;
	    }
	    if (putval("a", last_answer, "previous answer") != 0) {
		fprintf(stderr, "error storing last answer\n");
	    }
	}
    }

    if (cmdline_input) {
#ifdef HAVE_READLINE_HISTORY
	char filename[PATH_MAX];

	snprintf(filename, PATH_MAX, "%s/.wcalc_history", getenv("HOME"));
	if (write_history(filename))
	    perror("Saving History");
	if (conf.history_limit) {
	    if (history_truncate_file(filename, conf.history_limit_len))
		perror("Truncating History");
	}
#endif
	clearHistory();
	cleanupvar();
	num_free(last_answer);
	lists_cleanup();
	exit(EXIT_SUCCESS);
    }

    tty = isatty(0);		       /* Find out where stdin is coming from... */
    if (tty > 0) {
	/* if stdin is a keyboard or terminal, then use readline and prompts */
#ifdef HAVE_READLINE_HISTORY
	char filename[PATH_MAX];

	snprintf(filename, PATH_MAX, "%s/.wcalc_history", getenv("HOME"));
	using_history();
	if (read_history(filename)) {
	    if (errno != ENOENT) {
		perror("Reading History");
	    }
	}
#endif
#ifdef HAVE_LIBREADLINE
	rl_attempted_completion_function = wcalc_completion;
	rl_basic_word_break_characters = " \t\n\"\'+-*/[{()}]=<>!|~&^%";
#endif
	printf
	    ("Enter an expression to evaluate, q to quit, or ? for help:\n");
	while (1) {
	    lines = 1;
	    fflush(NULL);
#ifdef HAVE_LIBREADLINE
	    readme = readline("-> ");
#else
	    {
		char c;
		unsigned int i = 0;

		memset(readme, 0, BIG_STRING);
		printf("-> ");
		fflush(stdout);
		c = fgetc(stdin);
		while (c != '\n' && i < BIG_STRING && !feof(stdin) &&
		       !ferror(stdin)) {
		    readme[i] = c;
		    c = fgetc(stdin);
		    ++i;
		}
		if (feof(stdin) || ferror(stdin))
		    break;
	    }
#endif
	    if (!readme) {
		/* from the readline manpage:
		 *      readline returns the text of the line read. A blank
		 *      line returns the empty string. If EOF is encountered
		 *      while reading a line, and the line is empty, NULL is
		 *      returned. If an eof is read with a non-empty line, it
		 *      is treated as a newline.
		 * This means: readme == NULL is a perfectly reasonable
		 * response from readline(), AND it means something
		 * significant. DO NOT DO errno PARSING HERE!!!!
		 */
		printf("\n");
		break;
	    }
	    /* if there is a line */
	    if (strlen(readme)) {
		if (!strcmp(readme, "q") || !strcmp(readme, "quit") ||
		    !strcmp(readme, "\\q")) {
		    break;
		} else if (!strncmp(readme, "\\yydebug", 8)) {
		    //addToHistory(readme, 0);
		    yydebug = !yydebug;
		    printf("Debug Mode %s\n", yydebug ? "On" : "Off");
		} else {
		    if (conf.verbose) {
			printf("-> %s\n", readme);
		    }
		    parseme(readme);
		    {
			extern char *errstring;

			if (!errstring || (errstring && !strlen(errstring)) ||
			    conf.remember_errors) {
			    addToHistory(readme, last_answer);
			}
		    }
		}
		if (putval("a", last_answer, "previous answer") != 0) {
		    fprintf(stderr, "error storing last answer\n");
		}

		{
		    extern char *errstring;

		    if (errstring && strlen(errstring)) {
			display_and_clear_errstring();
			/*rl_stuff_char('f');*/
		    }
		}
	    }
#ifdef HAVE_LIBREADLINE
	    free(readme);
#endif
	}
#ifdef HAVE_READLINE_HISTORY
	if (write_history(filename))
	    perror("Saving History");
	if (conf.history_limit) {
	    if (history_truncate_file(filename, conf.history_limit_len))
		perror("Truncating History");
	}
#endif
    } else if (tty < 0) {
	fprintf(stderr, "Could not determine terminal type.\n");
    } else {
	/* if stdin is ANYTHING ELSE (a pipe, a file, etc), don't prompt */
	char *line, gotten;
	unsigned int linelen = 0, maxlinelen = BIG_STRING;
	extern int show_line_numbers;

	show_line_numbers = 1;
	while (1) {
	    line = calloc(maxlinelen, sizeof(char));
	    gotten = fgetc(stdin);
	    while (gotten != '\n' && !feof(stdin) && !ferror(stdin)) {
		line[linelen] = gotten;
		gotten = fgetc(stdin);
		linelen++;
		if (linelen > maxlinelen) {
		    char *temp;
		    temp = realloc(line, (maxlinelen + BIG_STRING) * sizeof(char));
		    if (!temp) {
			free(line);
			fprintf(stderr,
				"Ran out of memory. Line too long.\n");
			exit(EXIT_FAILURE);
		    }
		    memset(temp + maxlinelen, 0, BIG_STRING);
		    maxlinelen += BIG_STRING;
		    line = temp;
		}
	    }
	    if (ferror(stdin) || (feof(stdin) && linelen == 0)) {
		free(line);
		break;
	    }
	    if (conf.verbose) {
		printf("-> %s\n", line);
	    }
	    parseme(line);
	    if (putval("a", last_answer, "previous answer") != 0) {
		fprintf(stderr, "error storing last answer\n");
	    }
	    {
		extern int errloc;

		if (errloc != -1) {
		    errloc = -1;
		    display_and_clear_errstring();
		    /*fprintf(stderr, "%s", errstring);
		    if (errstring[strlen(errstring) - 1] != '\n')
			fprintf(stderr, "\n");
		    free(errstring);
		    errstring = NULL;*/
		}
	    }
	    free(line);
	    linelen = 0;
	}
    }

    clearHistory();
    cleanupvar();
    if (pretty_answer) {
	extern char *pa;

	free(pretty_answer);
	if (pa) {
	    free(pa);
	}
    }
    num_free(last_answer);
    lists_cleanup();
    exit(EXIT_SUCCESS);
}				       /*}}} */

static int read_preload(char *filename)
{				       /*{{{ */
    struct stat sb;

    if (-1 == stat(filename, &sb)) {
	if (errno != ENOENT) {
	    return -1;
	} else {
	    return 0;
	}
    }
    return loadState(filename, 0);
}				       /*}}} */

static int read_prefs(char *filename)
{				       /*{{{ */
    int fd = open(filename, O_RDONLY);
    char key[BIG_STRING], value[BIG_STRING];
    size_t curs = 0;
    int retval = 1;

    fd = open(filename, O_RDONLY);
    if (fd < 0)
	return 0;
    retval = 1;
    while (retval == 1) {
	char quoted = 0;
	char junk;

	memset(value, 0, BIG_STRING);
	memset(key, 0, BIG_STRING);

	curs = 0;
	// read until we find a non-comment
	while (1 == (retval = read(fd, &(key[curs]), 1))) {
	    // if we find a comment
	    if (key[curs] == '#') {
		// read until the end of line
		junk = 0;
		while (read(fd, &junk, 1) == 1 && junk != '\n') ;
	    } else if (isalpha((int)(key[curs])))
		break;
	}
	if (retval != 1)
	    break;
	// read in the key
	quoted = 1;
	if (key[curs] != '\'') {
	    curs++;
	    quoted = 0;
	}
	while (retval == 1 && curs < BIG_STRING) {
	    retval = read(fd, &(key[curs]), 1);
	    if ((!quoted && isspace((int)(key[curs]))) ||
		(!quoted && key[curs] == '=') ||
		(quoted && key[curs] != '\''))
		break;
	    ++curs;
	}
	if (retval != 1)
	    break;
	junk = key[curs];
	key[curs] = 0;
	// eat the equals sign (and any surrounding space)
	while (retval == 1 && (isspace((int)junk) || junk == '=')) {
	    retval = read(fd, &junk, 1);
	}
	if (retval != 1)
	    break;
	value[0] = junk; // junk now contains the next non-junk character
	curs = 0;
	// read in the value
	quoted = 1;
	if (value[0] != '\'') {
	    ++curs;
	    quoted = 0;
	}
	while (retval == 1 && value[curs-1] && curs < BIG_STRING) {
	    retval = read(fd, &(value[curs]), 1);
	    if ((!quoted && isspace((int)(value[curs]))) ||
		(quoted && value[curs] != '\''))
		break;
	    curs++;
	}
	value[curs] = 0;

	if (!strcmp(key, "precision"))
	    conf.precision = atoi(value);
	else if (!strcmp(key, "show_equals"))
	    conf.print_equal = TRUEFALSE;
	else if (!strcmp(key, "flag_undeclared"))
	    conf.picky_variables = TRUEFALSE;
	else if (!strcmp(key, "use_radians"))
	    conf.use_radians = TRUEFALSE;
	else if (!strcmp(key, "print_prefixes"))
	    conf.print_prefixes = TRUEFALSE;
	else if (!strcmp(key, "save_errors"))
	    conf.remember_errors = TRUEFALSE;
	else if (!strcmp(key, "remember_errors"))
	    conf.remember_errors = TRUEFALSE;
	else if (!strcmp(key, "precision_guard"))
	    conf.precision_guard = TRUEFALSE;
	else if (!strcmp(key, "print_integers"))
	    conf.print_ints = TRUEFALSE;
	else if (!strcmp(key, "print_delimiters"))
	    conf.print_commas = TRUEFALSE;
	else if (!strcmp(key, "input_thousands_delimiter"))
	    conf.in_thou_delimiter = value[0];
	else if (!strcmp(key, "input_decimal_delimiter"))
	    conf.in_dec_delimiter = value[0];
	else if (!strcmp(key, "thousands_delimiter"))
	    conf.thou_delimiter = value[0];
	else if (!strcmp(key, "decimal_delimiter"))
	    conf.dec_delimiter = value[0];
	else if (!strcmp(key, "history_limit")) {
	    if (!strcmp(value, "no"))
		conf.history_limit = conf.history_limit_len = 0;
	    else {
		conf.history_limit = 1;
		conf.history_limit_len = strtoul(value, NULL, 0);
	    }
	} else if (!strcmp(key, "output_format")) {
	    if (!strcmp(value, "decimal"))
		conf.output_format = DECIMAL_FORMAT;
	    else if (!strcmp(value, "octal"))
		conf.output_format = OCTAL_FORMAT;
	    else if (!strcmp(value, "binary"))
		conf.output_format = BINARY_FORMAT;
	    else if (!strcmp(value, "hex") || !strcmp(value, "hexadecimal"))
		conf.output_format = HEXADECIMAL_FORMAT;
	} else if (!strcmp(key, "rounding_indication")) {
	    if (!strcmp(value, "no"))
		conf.rounding_indication = NO_ROUNDING_INDICATION;
	    else if (!strcmp(value, "simple"))
		conf.rounding_indication = SIMPLE_ROUNDING_INDICATION;
	    else if (!strcmp(value, "sig_fig"))
		conf.rounding_indication = SIG_FIG_ROUNDING_INDICATION;
	} else if (!strcmp(key, "engineering")) {
	    if (!strcmp(value,"auto") || !strcmp(value,"automatic") || !strcmp(value,"yes") || !strcmp(value,"true") || !strcmp(value,"1")) {
		conf.engineering = automatic;
	    } else if (!strcmp(value, "always")) {
		conf.engineering = always;
	    } else {
		conf.engineering = never;
	    }
	} else if (!strcmp(key, "c_style_mod")) {
	    conf.c_style_mod = TRUEFALSE;
	} else {
	    fprintf(stderr, "Unrecognized key in wcalcrc: %s\n", key);
	}
	memset(key, 0, sizeof(key));
	memset(value, 0, sizeof(value));
    }
    return 0;
}				       /*}}} */