4.4BSD/usr/src/bin/test/test.c
/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1992, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)test.c 8.1 (Berkeley) 5/31/93";
#endif /* not lint */
#include <sys/types.h>
#include <sys/stat.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "operators.h"
#define STACKSIZE 12
#define NESTINCR 16
/* data types */
#define STRING 0
#define INTEGER 1
#define BOOLEAN 2
#define IS_BANG(s) (s[0] == '!' && s[1] == '\0')
/*
* This structure hold a value. The type keyword specifies the type of
* the value, and the union u holds the value. The value of a boolean
* is stored in u.num (1 = TRUE, 0 = FALSE).
*/
struct value {
int type;
union {
char *string;
long num;
} u;
};
struct operator {
short op; /* Which operator. */
short pri; /* Priority of operator. */
};
struct filestat {
char *name; /* Name of file. */
int rcode; /* Return code from stat. */
struct stat stat; /* Status info on file. */
};
static int expr_is_false __P((struct value *));
static void expr_operator __P((int, struct value *, struct filestat *));
static void get_int __P((char *, long *));
static int lookup_op __P((char *, char *const *));
static void overflow __P((void));
static int posix_binary_op __P((char **));
static int posix_unary_op __P((char **));
static void syntax __P((void));
int
main(argc, argv)
int argc;
char *argv[];
{
struct operator opstack[STACKSIZE];
struct operator *opsp;
struct value valstack[STACKSIZE + 1];
struct value *valsp;
struct filestat fs;
char c, **ap, *opname, *p;
int binary, nest, op, pri, ret_val, skipping;
if ((p = argv[0]) == NULL)
errx(2, "test: argc is zero");
if (*p != '\0' && p[strlen(p) - 1] == '[') {
if (strcmp(argv[--argc], "]"))
errx(2, "missing ]");
argv[argc] = NULL;
}
ap = argv + 1;
fs.name = NULL;
/*
* Test(1) implements an inherently ambiguous grammer. In order to
* assure some degree of consistency, we special case the POSIX 1003.2
* requirements to assure correct evaluation for POSIX scripts. The
* following special cases comply with POSIX P1003.2/D11.2 Section
* 4.62.4.
*/
switch(argc - 1) {
case 0: /* % test */
return (1);
break;
case 1: /* % test arg */
return (argv[1] == NULL || *argv[1] == '\0') ? 1 : 0;
break;
case 2: /* % test op arg */
opname = argv[1];
if (IS_BANG(opname))
return (*argv[2] == '\0') ? 0 : 1;
else {
ret_val = posix_unary_op(&argv[1]);
if (ret_val >= 0)
return (ret_val);
}
break;
case 3: /* % test arg1 op arg2 */
if (IS_BANG(argv[1])) {
ret_val = posix_unary_op(&argv[1]);
if (ret_val >= 0)
return (!ret_val);
} else {
ret_val = posix_binary_op(&argv[1]);
if (ret_val >= 0)
return (ret_val);
}
break;
case 4: /* % test ! arg1 op arg2 */
if (IS_BANG(argv[1])) {
ret_val = posix_binary_op(&argv[2]);
if (ret_val >= 0)
return (!ret_val);
}
break;
default:
break;
}
/*
* We use operator precedence parsing, evaluating the expression as
* we parse it. Parentheses are handled by bumping up the priority
* of operators using the variable "nest." We use the variable
* "skipping" to turn off evaluation temporarily for the short
* circuit boolean operators. (It is important do the short circuit
* evaluation because under NFS a stat operation can take infinitely
* long.)
*/
opsp = opstack + STACKSIZE;
valsp = valstack;
nest = skipping = 0;
if (*ap == NULL) {
valstack[0].type = BOOLEAN;
valstack[0].u.num = 0;
goto done;
}
for (;;) {
opname = *ap++;
if (opname == NULL)
syntax();
if (opname[0] == '(' && opname[1] == '\0') {
nest += NESTINCR;
continue;
} else if (*ap && (op = lookup_op(opname, unary_op)) >= 0) {
if (opsp == &opstack[0])
overflow();
--opsp;
opsp->op = op;
opsp->pri = op_priority[op] + nest;
continue;
} else {
valsp->type = STRING;
valsp->u.string = opname;
valsp++;
}
for (;;) {
opname = *ap++;
if (opname == NULL) {
if (nest != 0)
syntax();
pri = 0;
break;
}
if (opname[0] != ')' || opname[1] != '\0') {
if ((op = lookup_op(opname, binary_op)) < 0)
syntax();
op += FIRST_BINARY_OP;
pri = op_priority[op] + nest;
break;
}
if ((nest -= NESTINCR) < 0)
syntax();
}
while (opsp < &opstack[STACKSIZE] && opsp->pri >= pri) {
binary = opsp->op;
for (;;) {
valsp--;
c = op_argflag[opsp->op];
if (c == OP_INT) {
if (valsp->type == STRING)
get_int(valsp->u.string,
&valsp->u.num);
valsp->type = INTEGER;
} else if (c >= OP_STRING) {
/* OP_STRING or OP_FILE */
if (valsp->type == INTEGER) {
if ((p = malloc(32)) == NULL)
err(2, NULL);
#ifdef SHELL
fmtstr(p, 32, "%d",
valsp->u.num);
#else
(void)sprintf(p,
"%d", valsp->u.num);
#endif
valsp->u.string = p;
} else if (valsp->type == BOOLEAN) {
if (valsp->u.num)
valsp->u.string =
"true";
else
valsp->u.string = "";
}
valsp->type = STRING;
if (c == OP_FILE && (fs.name == NULL ||
strcmp(fs.name, valsp->u.string))) {
fs.name = valsp->u.string;
fs.rcode =
stat(valsp->u.string,
&fs.stat);
}
}
if (binary < FIRST_BINARY_OP)
break;
binary = 0;
}
if (!skipping)
expr_operator(opsp->op, valsp, &fs);
else if (opsp->op == AND1 || opsp->op == OR1)
skipping--;
valsp++; /* push value */
opsp++; /* pop operator */
}
if (opname == NULL)
break;
if (opsp == &opstack[0])
overflow();
if (op == AND1 || op == AND2) {
op = AND1;
if (skipping || expr_is_false(valsp - 1))
skipping++;
}
if (op == OR1 || op == OR2) {
op = OR1;
if (skipping || !expr_is_false(valsp - 1))
skipping++;
}
opsp--;
opsp->op = op;
opsp->pri = pri;
}
done: return (expr_is_false(&valstack[0]));
}
static int
expr_is_false(val)
struct value *val;
{
if (val->type == STRING) {
if (val->u.string[0] == '\0')
return (1);
} else { /* INTEGER or BOOLEAN */
if (val->u.num == 0)
return (1);
}
return (0);
}
/*
* Execute an operator. Op is the operator. Sp is the stack pointer;
* sp[0] refers to the first operand, sp[1] refers to the second operand
* (if any), and the result is placed in sp[0]. The operands are converted
* to the type expected by the operator before expr_operator is called.
* Fs is a pointer to a structure which holds the value of the last call
* to stat, to avoid repeated stat calls on the same file.
*/
static void
expr_operator(op, sp, fs)
int op;
struct value *sp;
struct filestat *fs;
{
int i;
switch (op) {
case NOT:
sp->u.num = expr_is_false(sp);
sp->type = BOOLEAN;
break;
case ISEXIST:
if (fs == NULL || fs->rcode == -1)
goto false;
else
goto true;
case ISREAD:
i = S_IROTH;
goto permission;
case ISWRITE:
i = S_IWOTH;
goto permission;
case ISEXEC:
i = S_IXOTH;
permission: if (fs->stat.st_uid == geteuid())
i <<= 6;
else if (fs->stat.st_gid == getegid())
i <<= 3;
goto filebit; /* true if (stat.st_mode & i) != 0 */
case ISFILE:
i = S_IFREG;
goto filetype;
case ISDIR:
i = S_IFDIR;
goto filetype;
case ISCHAR:
i = S_IFCHR;
goto filetype;
case ISBLOCK:
i = S_IFBLK;
goto filetype;
case ISSYMLINK:
i = S_IFLNK;
(void)lstat(sp->u.string, &fs->stat);
goto filetype;
case ISFIFO:
i = S_IFIFO;
goto filetype;
filetype: if ((fs->stat.st_mode & S_IFMT) == i && fs->rcode >= 0)
true: sp->u.num = 1;
else
false: sp->u.num = 0;
sp->type = BOOLEAN;
break;
case ISSETUID:
i = S_ISUID;
goto filebit;
case ISSETGID:
i = S_ISGID;
goto filebit;
case ISSTICKY:
i = S_ISVTX;
filebit: if (fs->stat.st_mode & i && fs->rcode >= 0)
goto true;
goto false;
case ISSIZE:
sp->u.num = fs->rcode >= 0 ? fs->stat.st_size : 0L;
sp->type = INTEGER;
break;
case ISTTY:
sp->u.num = isatty(sp->u.num);
sp->type = BOOLEAN;
break;
case NULSTR:
if (sp->u.string[0] == '\0')
goto true;
goto false;
case STRLEN:
sp->u.num = strlen(sp->u.string);
sp->type = INTEGER;
break;
case OR1:
case AND1:
/*
* These operators are mostly handled by the parser. If we
* get here it means that both operands were evaluated, so
* the value is the value of the second operand.
*/
*sp = *(sp + 1);
break;
case STREQ:
case STRNE:
i = 0;
if (!strcmp(sp->u.string, (sp + 1)->u.string))
i++;
if (op == STRNE)
i = 1 - i;
sp->u.num = i;
sp->type = BOOLEAN;
break;
case EQ:
if (sp->u.num == (sp + 1)->u.num)
goto true;
goto false;
case NE:
if (sp->u.num != (sp + 1)->u.num)
goto true;
goto false;
case GT:
if (sp->u.num > (sp + 1)->u.num)
goto true;
goto false;
case LT:
if (sp->u.num < (sp + 1)->u.num)
goto true;
goto false;
case LE:
if (sp->u.num <= (sp + 1)->u.num)
goto true;
goto false;
case GE:
if (sp->u.num >= (sp + 1)->u.num)
goto true;
goto false;
}
}
static int
lookup_op(name, table)
char *name;
char *const * table;
{
register char *const * tp;
register char const *p;
char c;
c = name[1];
for (tp = table; (p = *tp) != NULL; tp++)
if (p[1] == c && !strcmp(p, name))
return (tp - table);
return (-1);
}
static int
posix_unary_op(argv)
char **argv;
{
struct filestat fs;
struct value valp;
int op, c;
char *opname;
opname = *argv;
if ((op = lookup_op(opname, unary_op)) < 0)
return (-1);
c = op_argflag[op];
opname = argv[1];
valp.u.string = opname;
if (c == OP_FILE) {
fs.name = opname;
fs.rcode = stat(opname, &fs.stat);
} else if (c != OP_STRING)
return (-1);
expr_operator(op, &valp, &fs);
return (valp.u.num == 0);
}
static int
posix_binary_op(argv)
char **argv;
{
struct value v[2];
int op, c;
char *opname;
opname = argv[1];
if ((op = lookup_op(opname, binary_op)) < 0)
return (-1);
op += FIRST_BINARY_OP;
c = op_argflag[op];
if (c == OP_INT) {
get_int(argv[0], &v[0].u.num);
get_int(argv[2], &v[1].u.num);
} else {
v[0].u.string = argv[0];
v[1].u.string = argv[2];
}
expr_operator(op, v, NULL);
return (v[0].u.num == 0);
}
/*
* Integer type checking.
*/
static void
get_int(v, lp)
char *v;
long *lp;
{
long val;
char *ep;
for (; *v && isspace(*v); ++v);
if (isdigit(*v)) {
errno = 0;
val = strtol(v, &ep, 10);
if (*ep != '\0')
errx(2, "%s: trailing non-numeric characters", v);
if (errno == ERANGE) {
if (val == LONG_MIN)
errx(2, "%s: underflow", v);
if (val == LONG_MAX)
errx(2, "%s: overflow", v);
}
*lp = val;
return;
}
errx(2, "%s: expected integer", v);
}
static void
syntax()
{
err(2, "syntax error");
}
static void
overflow()
{
err(2, "expression is too complex");
}