openenvutils/commandshell/shell/src/cond.c
author William Roberts <williamr@symbian.org>
Fri, 23 Apr 2010 14:37:17 +0100
branchRCL_3
changeset 22 c82a39b81a38
parent 0 2e3d3ce01487
permissions -rw-r--r--
Rework addition of Symbian splash screen to reduce the source impact (uses SVG from Bug 2414) Notes: by using the OPTION SOURCEDIR parameter in the mifconv extension instructions, I can arrange to use the same source file name in sfimage, without having to export over the original Nokia file. This means that the name inside splashscreen.mbg is the same, which removes the need for the conditional compilation in SplashScreen.cpp, and gets rid of sf_splashscreen.mmp.

/*
 * cond.c - evaluate conditional expressions
 *
 * This file is part of zsh, the Z shell.
 *
 * Copyright (c) 1992-1997 Paul Falstad
 * All rights reserved.
 *
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and to distribute modified versions of this software for any
 * purpose, provided that the above copyright notice and the following
 * two paragraphs appear in all copies of this software.
 *
 * In no event shall Paul Falstad or the Zsh Development Group be liable
 * to any party for direct, indirect, special, incidental, or consequential
 * damages arising out of the use of this software and its documentation,
 * even if Paul Falstad and the Zsh Development Group have been advised of
 * the possibility of such damage.
 *
 * Paul Falstad and the Zsh Development Group specifically disclaim any
 * warranties, including, but not limited to, the implied warranties of
 * merchantability and fitness for a particular purpose.  The software
 * provided hereunder is on an "as is" basis, and Paul Falstad and the
 * Zsh Development Group have no obligation to provide maintenance,
 * support, updates, enhancements, or modifications.
 *
 */

#include "zsh.mdh"
#include "cond.pro"

int tracingcond;

static char *condstr[COND_MOD] = {
    "!", "&&", "||", "==", "!=", "<", ">", "-nt", "-ot", "-ef", "-eq",
    "-ne", "-lt", "-gt", "-le", "-ge"
};

/*
 * Evaluate a conditional expression given the arguments.
 * If fromtest is set, the caller is the test or [ builtin;
 * with the pointer giving the name of the command.
 * for POSIX conformance this supports a more limited range
 * of functionality.
 *
 * Return status is the final shell status, i.e. 0 for true,
 * 1 for false and 2 for error.
 */

/**/
int
evalcond(Estate state, char *fromtest)
{
    struct stat *st;
    char *left, *right;
    Wordcode pcode;
    wordcode code;
    int ctype, htok = 0, ret;

 rec:

    left = right = NULL;
    pcode = state->pc++;
    code = *pcode;
    ctype = WC_COND_TYPE(code);

    switch (ctype) {
    case COND_NOT:
	if (tracingcond)
	    fprintf(xtrerr, " %s", condstr[ctype]);
	ret = evalcond(state, fromtest);
	if (ret == 2)
	    return ret;
	else
	    return !ret;
    case COND_AND:
	if (!(ret = evalcond(state, fromtest))) {
	    if (tracingcond)
		fprintf(xtrerr, " %s", condstr[ctype]);
	    goto rec;
	} else {
	    state->pc = pcode + (WC_COND_SKIP(code) + 1);
	    return ret;
	}
    case COND_OR:
	if ((ret = evalcond(state, fromtest)) == 1) {
	    if (tracingcond)
		fprintf(xtrerr, " %s", condstr[ctype]);
	    goto rec;
	} else {
	    state->pc = pcode + (WC_COND_SKIP(code) + 1);
	    return ret;
	}
    case COND_MOD:
    case COND_MODI:
	{
	    Conddef cd;
	    char *name = ecgetstr(state, EC_NODUP, NULL), **strs;
	    int l = WC_COND_SKIP(code);

	    if (ctype == COND_MOD)
		strs = ecgetarr(state, l, EC_DUP, NULL);
	    else {
		char *sbuf[3];

		sbuf[0] = ecgetstr(state, EC_NODUP, NULL);
		sbuf[1] = ecgetstr(state, EC_NODUP, NULL);
		sbuf[2] = NULL;

		strs = arrdup(sbuf);
		l = 2;
	    }
	    if ((cd = getconddef((ctype == COND_MODI), name + 1, 1))) {
		if (ctype == COND_MOD &&
		    (l < cd->min || (cd->max >= 0 && l > cd->max))) {
		    zwarnnam(fromtest, "unrecognized condition: `%s'",
			     name, 0);
		    return 2;
		}
		if (tracingcond)
		    tracemodcond(name, strs, ctype == COND_MODI);
		return !cd->handler(strs, cd->condid);
	    }
	    else {
		char *s = strs[0];

		strs[0] = dupstring(name);
		name = s;

		if (name && name[0] == '-' &&
		    (cd = getconddef(0, name + 1, 1))) {
		    if (l < cd->min || (cd->max >= 0 && l > cd->max)) {
			zwarnnam(fromtest, "unrecognized condition: `%s'",
				 name, 0);
			return 2;
		    }
		    if (tracingcond)
			tracemodcond(name, strs, ctype == COND_MODI);
		    return !cd->handler(strs, cd->condid);
		} else {
		    zwarnnam(fromtest,
			     "unrecognized condition: `%s'", name, 0);
		}
	    }
	    /* module not found, error */
	    return 2;
	}
    }
    left = ecgetstr(state, EC_DUPTOK, &htok);
    if (htok) {
	singsub(&left);
	untokenize(left);
    }
    if (ctype <= COND_GE && ctype != COND_STREQ && ctype != COND_STRNEQ) {
	right = ecgetstr(state, EC_DUPTOK, &htok);
	if (htok) {
	    singsub(&right);
	    untokenize(right);
	}
    }
    if (tracingcond) {
	if (ctype < COND_MOD) {
	    char *rt = (char *) right;
	    if (ctype == COND_STREQ || ctype == COND_STRNEQ) {
		rt = dupstring(ecrawstr(state->prog, state->pc, NULL));
		singsub(&rt);
		untokenize(rt);
	    }
	    fputc(' ',xtrerr);
	    quotedzputs(left, xtrerr);
	    fprintf(xtrerr, " %s ", condstr[ctype]);
	    quotedzputs(rt, xtrerr);
	} else {
	    fprintf(xtrerr, " -%c ", ctype);
	    quotedzputs(left, xtrerr);
	}
    }

    if (ctype >= COND_EQ && ctype <= COND_GE) {
	mnumber mn1, mn2;
	if (fromtest) {
	    /*
	     * For test and [, the expressions must be base 10 integers,
	     * not integer expressions.
	     */
	    char *eptr, *err;

	    mn1.u.l = zstrtol(left, &eptr, 10);
	    if (!*eptr)
	    {
		mn2.u.l = zstrtol(right, &eptr, 10);
		err = right;
	    }
	    else
		err = left;

	    if (*eptr)
	    {
		zwarnnam(fromtest, "integer expression expected: %s",
			 err, 0);
		return 2;
	    }

	    mn1.type = mn2.type = MN_INTEGER;
	} else {
	    mn1 = matheval(left);
	    mn2 = matheval(right);
	}

	if (((mn1.type|mn2.type) & (MN_INTEGER|MN_FLOAT)) ==
	    (MN_INTEGER|MN_FLOAT)) {
	    /* promote to float */
	    if (mn1.type & MN_INTEGER) {
		mn1.type = MN_FLOAT;
		mn1.u.d = (double)mn1.u.l;
	    }
	    if (mn2.type & MN_INTEGER) {
		mn2.type = MN_FLOAT;
		mn2.u.d = (double)mn2.u.l;
	    }
	}
	switch(ctype) {
	case COND_EQ:
	    return !((mn1.type & MN_FLOAT) ? (mn1.u.d == mn2.u.d) :
		     (mn1.u.l == mn2.u.l));
	case COND_NE:
	    return !((mn1.type & MN_FLOAT) ? (mn1.u.d != mn2.u.d) :
		     (mn1.u.l != mn2.u.l));
	case COND_LT:
	    return !((mn1.type & MN_FLOAT) ? (mn1.u.d < mn2.u.d) :
		     (mn1.u.l < mn2.u.l));
	case COND_GT:
	    return !((mn1.type & MN_FLOAT) ? (mn1.u.d > mn2.u.d) :
		     (mn1.u.l > mn2.u.l));
	case COND_LE:
	    return !((mn1.type & MN_FLOAT) ? (mn1.u.d <= mn2.u.d) :
		     (mn1.u.l <= mn2.u.l));
	case COND_GE:
	    return !((mn1.type & MN_FLOAT) ? (mn1.u.d >= mn2.u.d) :
		     (mn1.u.l >= mn2.u.l));
	}
    }

    switch (ctype) {
    case COND_STREQ:
    case COND_STRNEQ:
	{
	    int test, npat = state->pc[1];
	    Patprog pprog = state->prog->pats[npat];

	    if (pprog == dummy_patprog1 || pprog == dummy_patprog2) {
		char *opat;
		int save;

		right = dupstring(opat = ecrawstr(state->prog, state->pc,
						  &htok));
		if (htok)
		    singsub(&right);
		save = (!(state->prog->flags & EF_HEAP) &&
			!strcmp(opat, right) && pprog != dummy_patprog2);

		if (!(pprog = patcompile(right, (save ? PAT_ZDUP : PAT_STATIC),
					 NULL))) {
		    zwarnnam(fromtest, "bad pattern: %s", right, 0);
		    return 2;
		}
		else if (save)
		    state->prog->pats[npat] = pprog;
	    }
	    state->pc += 2;
	    test = (pprog && pattry(pprog, left));

	    return !(ctype == COND_STREQ ? test : !test);
	}
    case COND_STRLT:
	return !(strcmp(left, right) < 0);
    case COND_STRGTR:
	return !(strcmp(left, right) > 0);
    case 'e':
    case 'a':
	return (!doaccess(left, F_OK));
    case 'b':
	return (!S_ISBLK(dostat(left)));
    case 'c':
	return (!S_ISCHR(dostat(left)));
    case 'd':
	return (!S_ISDIR(dostat(left)));
    case 'f':
	return (!S_ISREG(dostat(left)));
    case 'g':
	return (!(dostat(left) & S_ISGID));
    case 'k':
	return (!(dostat(left) & S_ISVTX));
    case 'n':
	return (!strlen(left));
    case 'o':
	return (optison(fromtest, left));
    case 'p':
	return (!S_ISFIFO(dostat(left)));
    case 'r':
	return (!doaccess(left, R_OK));
    case 's':
	return !((st = getstat(left)) && !!(st->st_size));
    case 'S':
	return (!S_ISSOCK(dostat(left)));
    case 'u':
	return (!(dostat(left) & S_ISUID));
    case 'w':
	return (!doaccess(left, W_OK));
    case 'x':
	if (privasserted()) {
	    mode_t mode = dostat(left);
	    return !((mode & S_IXUGO) || S_ISDIR(mode));
	}
	return !doaccess(left, X_OK);
    case 'z':
	return !!(strlen(left));
    case 'h':
    case 'L':
	return (!S_ISLNK(dolstat(left)));
    case 'O':
	return !((st = getstat(left)) && st->st_uid == geteuid());
    case 'G':
	return !((st = getstat(left)) && st->st_gid == getegid());
    case 'N':
	return !((st = getstat(left)) && st->st_atime <= st->st_mtime);
    case 't':
	return !isatty(mathevali(left));
    case COND_NT:
    case COND_OT:
	{
	    time_t a;

	    if (!(st = getstat(left)))
		return 1;
	    a = st->st_mtime;
	    if (!(st = getstat(right)))
		return 1;
	    return !((ctype == COND_NT) ? a > st->st_mtime : a < st->st_mtime);
	}
    case COND_EF:
	{
	    dev_t d;
	    ino_t i;

	    if (!(st = getstat(left)))
		return 1;
	    d = st->st_dev;
	    i = st->st_ino;
	    if (!(st = getstat(right)))
		return 1;
	    return !(d == st->st_dev && i == st->st_ino);
	}
    default:
	zwarnnam(fromtest, "bad cond code", NULL, 0);
	return 2;
    }
    return 1;
}


/**/
static int
doaccess(char *s, int c)
{
#ifdef HAVE_FACCESSX
    if (!strncmp(s, "/dev/fd/", 8))
	return !faccessx(atoi(s + 8), c, ACC_SELF);
#endif
    return !access(unmeta(s), c);
}


static struct stat st;

/**/
static struct stat *
getstat(char *s)
{
    char *us;

/* /dev/fd/n refers to the open file descriptor n.  We always use fstat *
 * in this case since on Solaris /dev/fd/n is a device special file     */
    if (!strncmp(s, "/dev/fd/", 8)) {
	if (fstat(atoi(s + 8), &st))
	    return NULL;
        return &st;
    }

    if (!(us = unmeta(s)))
        return NULL;
    if (stat(us, &st))
	return NULL;
    return &st;
}


/**/
static mode_t
dostat(char *s)
{
    struct stat *statp;

    if (!(statp = getstat(s)))
	return 0;
    return statp->st_mode;
}


/* pem@aaii.oz; needed since dostat now uses "stat" */

/**/
static mode_t
dolstat(char *s)
{
    if (lstat(unmeta(s), &st) < 0)
	return 0;
    return st.st_mode;
}


/*
 * optison returns evalcond-friendly statuses (true, false, error).
 */

/**/
static int
optison(char *name, char *s)
{
    int i;

    if (strlen(s) == 1)
	i = optlookupc(*s);
    else
	i = optlookup(s);
    if (!i) {
	zwarnnam(name, "no such option: %s", s, 0);
	return 2;
    } else if(i < 0)
	return !unset(-i);
    else
	return !isset(i);
}

/**/
mod_export char *
cond_str(char **args, int num, int raw)
{
    char *s = args[num];

    if (has_token(s)) {
	singsub(&s);
	if (!raw)
	    untokenize(s);
    }
    return s;
}

/**/
mod_export zlong
cond_val(char **args, int num)
{
    char *s = args[num];

    if (has_token(s)) {
	singsub(&s);
	untokenize(s);
    }
    return mathevali(s);
}

/**/
mod_export int
cond_match(char **args, int num, char *str)
{
    char *s = args[num];

    singsub(&s);

    return matchpat(str, s);
}

/**/
static void
tracemodcond(char *name, char **args, int inf)
{
    char **aptr;

    args = arrdup(args);
    for (aptr = args; *aptr; aptr++)
	untokenize(*aptr);
    if (inf) {
	fprintf(xtrerr, " %s %s %s", args[0], name, args[1]);
    } else {
	fprintf(xtrerr, " %s", name);
	while (*args)
	    fprintf(xtrerr, " %s", *args++);
    }
}