From: Lionel Sambuc Date: Wed, 30 Jan 2013 17:52:21 +0000 (+0100) Subject: Importing NetBSD expr X-Git-Tag: v3.2.1~40 X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zpipe.c?a=commitdiff_plain;h=refs%2Fchanges%2F77%2F277%2F2;p=minix.git Importing NetBSD expr Change-Id: Ifdb1160cbfeb1324f6fcd612e66112fa0940227c --- diff --git a/bin/Makefile b/bin/Makefile index 218137b64..471e2039c 100644 --- a/bin/Makefile +++ b/bin/Makefile @@ -1,7 +1,7 @@ # $NetBSD: Makefile,v 1.22 2007/12/31 15:31:24 ad Exp $ # @(#)Makefile 8.1 (Berkeley) 5/31/93 -SUBDIR= cat date echo ed \ +SUBDIR= cat date echo ed expr \ mkdir pax rm rmdir test .include diff --git a/bin/expr/Makefile b/bin/expr/Makefile new file mode 100644 index 000000000..7c7612fca --- /dev/null +++ b/bin/expr/Makefile @@ -0,0 +1,6 @@ +# $NetBSD: Makefile,v 1.14 2000/09/19 17:20:00 jdolecek Exp $ + +PROG= expr +SRCS= expr.y + +.include diff --git a/bin/expr/expr.1 b/bin/expr/expr.1 new file mode 100644 index 000000000..3fe39c420 --- /dev/null +++ b/bin/expr/expr.1 @@ -0,0 +1,267 @@ +.\" $NetBSD: expr.1,v 1.33 2012/08/12 17:27:04 wiz Exp $ +.\" +.\" Copyright (c) 2000,2003 The NetBSD Foundation, Inc. +.\" All rights reserved. +.\" +.\" This code is derived from software contributed to The NetBSD Foundation +.\" by J.T. Conklin and Jaromir Dolecek . +.\" +.\" 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. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. +.\" +.Dd April 20, 2004 +.Dt EXPR 1 +.Os +.Sh NAME +.Nm expr +.Nd evaluate expression +.Sh SYNOPSIS +.Nm +.Ar expression +.Sh DESCRIPTION +The +.Nm +utility evaluates +.Ar expression +and writes the result on standard output. +.Pp +All operators are separate arguments to the +.Nm +utility. +Characters special to the command interpreter must be escaped. +.Pp +Operators are listed below in order of increasing precedence. +Operators with equal precedence are grouped within { } symbols. +.Bl -tag -width indent +.It Ar expr1 Li \&| Ar expr2 +Returns the evaluation of +.Ar expr1 +if it is neither an empty string nor zero; +otherwise, returns the evaluation of +.Ar expr2 . +.It Ar expr1 Li \*[Am] Ar expr2 +Returns the evaluation of +.Ar expr1 +if neither expression evaluates to an empty string or zero; +otherwise, returns zero. +.It Ar expr1 Li "{=, \*[Gt], \*[Ge], \*[Lt], \*[Le], !=}" Ar expr2 +Returns the results of integer comparison if both arguments are integers; +otherwise, returns the results of string comparison using the locale-specific +collation sequence. +The result of each comparison is 1 if the specified relation is true, +or 0 if the relation is false. +.It Ar expr1 Li "{+, -}" Ar expr2 +Returns the results of addition or subtraction of integer-valued arguments. +.It Ar expr1 Li "{*, /, %}" Ar expr2 +Returns the results of multiplication, integer division, or remainder of integer-valued arguments. +.It Ar expr1 Li \&: Ar expr2 +The +.Dq \&: +operator matches +.Ar expr1 +against +.Ar expr2 , +which must be a regular expression. +The regular expression is anchored +to the beginning of the string with an implicit +.Dq ^ . +.Pp +If the match succeeds and the pattern contains at least one regular +expression subexpression +.Dq "\e(...\e)" , +the string corresponding to +.Dq "\e1" +is returned; +otherwise the matching operator returns the number of characters matched. +If the match fails and the pattern contains a regular expression subexpression +the null string is returned; +otherwise 0. +.It "( " Ar expr No " )" +Parentheses are used for grouping in the usual manner. +.El +.Pp +Additionally, the following keywords are recognized: +.Bl -tag -width indent +.It length Ar expr +Returns the length of the specified string in bytes. +.El +.Pp +Operator precedence (from highest to lowest): +.Bl -enum -compact -offset indent +.It +parentheses +.It +length +.It +.Dq \&: +.It +.Dq "*" , +.Dq "/" , +and +.Dq "%" +.It +.Dq "+" +and +.Dq "-" +.It +compare operators +.It +.Dq \*[Am] +.It +.Dq \&| +.El +.Sh EXIT STATUS +The +.Nm +utility exits with one of the following values: +.Bl -tag -width Ds -compact +.It 0 +the expression is neither an empty string nor 0. +.It 1 +the expression is an empty string or 0. +.It 2 +the expression is invalid. +.It \*[Gt]2 +an error occurred (such as memory allocation failure). +.El +.Sh EXAMPLES +.Bl -enum +.It +The following example adds one to variable +.Dq a : +.Dl a=`expr $a + 1` +.It +The following example returns zero, due to subtraction having higher precedence +than the +.Dq \*[Am] +operator: +.Dl expr 1 '\*[Am]' 1 - 1 +.It +The following example returns the filename portion of a pathname stored +in variable +.Dq a : +.Dl expr "/$a" Li : '.*/\e(.*\e)' +.It +The following example returns the number of characters in variable +.Dq a : +.Dl expr $a Li : '.*' +.El +.Sh COMPATIBILITY +This implementation of +.Nm +internally uses 64 bit representation of integers and checks for +over- and underflows. +It also treats +.Dq / +(the division mark) and option +.Dq -- +correctly depending upon context. +.Pp +.Nm +on other systems (including +.Nx +up to and including +.Nx 1.5 ) +might not be so graceful. +Arithmetic results might be arbitrarily +limited on such systems, most commonly to 32 bit quantities. +This means such +.Nm +can only process values between -2147483648 and +2147483647. +.Pp +On other systems, +.Nm +might also not work correctly for regular expressions where +either side contains +.Dq / +(a single forward slash), like this: +.Bd -literal -offset indent +expr / : '.*/\e(.*\e)' +.Ed +.Pp +If this is the case, you might use +.Dq // +(a double forward slash) +to avoid confusion with the division operator: +.Bd -literal -offset indent +expr "//$a" : '.*/\e(.*\e)' +.Ed +.Pp +According to +.St -p1003.2 , +.Nm +has to recognize special option +.Dq -- , +treat it as a delimiter to mark the end of command +line options, and ignore it. +Some +.Nm +implementations don't recognize it at all; others +might ignore it even in cases where doing so results in syntax +error. +There should be same result for both following examples, +but it might not always be: +.Bl -enum -compact -offset indent +.It +expr -- : . +.It +expr -- -- : . +.El +Although +.Nx +.Nm +handles both cases correctly, you should not depend on this behavior +for portability reasons and avoid passing a bare +.Dq -- +as the first +argument. +.Sh STANDARDS +The +.Nm +utility conforms to +.St -p1003.2 . +The +.Ar length +keyword is an extension for compatibility with GNU +.Nm . +.Sh AUTHORS +Original implementation was written by +.An J.T. Conklin +.Aq jtc@NetBSD.org . +It was rewritten for +.Nx 1.6 +by +.An Jaromir Dolecek +.Aq jdolecek@NetBSD.org . +.Sh NOTES +The empty string +.Do Dc +cannot be matched with the intuitive: +.Bd -literal -offset indent +expr '' : '$' +.Ed +.Pp +The reason is that the returned number of matched characters (zero) +is indistinguishable from a failed match, so this returns failure. +To match the empty string, use something like: +.Bd -literal -offset indent +expr x'' : 'x$' +.Ed diff --git a/bin/expr/expr.y b/bin/expr/expr.y new file mode 100644 index 000000000..f368b6ee8 --- /dev/null +++ b/bin/expr/expr.y @@ -0,0 +1,459 @@ +/* $NetBSD: expr.y,v 1.38 2012/03/15 02:02:20 joerg Exp $ */ + +/*_ + * Copyright (c) 2000 The NetBSD Foundation, Inc. + * All rights reserved. + * + * This code is derived from software contributed to The NetBSD Foundation + * by Jaromir Dolecek and J.T. Conklin . + * + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. + */ + +%{ +#include +#ifndef lint +__RCSID("$NetBSD: expr.y,v 1.38 2012/03/15 02:02:20 joerg Exp $"); +#endif /* not lint */ + +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static const char * const *av; + +static void yyerror(const char *, ...) __dead; +static int yylex(void); +static int is_zero_or_null(const char *); +static int is_integer(const char *); +static int64_t perform_arith_op(const char *, const char *, const char *); + +int main(int, const char * const *); + +#define YYSTYPE const char * + +%} +%token STRING +%left SPEC_OR +%left SPEC_AND +%left COMPARE +%left ADD_SUB_OPERATOR +%left MUL_DIV_MOD_OPERATOR +%left SPEC_REG +%left LENGTH +%left LEFT_PARENT RIGHT_PARENT + +%% + +exp: expr = { + (void) printf("%s\n", $1); + return (is_zero_or_null($1)); + } + ; + +expr: item { $$ = $1; } + | expr SPEC_OR expr = { + /* + * Return evaluation of first expression if it is neither + * an empty string nor zero; otherwise, returns the evaluation + * of second expression. + */ + if (!is_zero_or_null($1)) + $$ = $1; + else + $$ = $3; + } + | expr SPEC_AND expr = { + /* + * Returns the evaluation of first expr if neither expression + * evaluates to an empty string or zero; otherwise, returns + * zero. + */ + if (!is_zero_or_null($1) && !is_zero_or_null($3)) + $$ = $1; + else + $$ = "0"; + } + | expr SPEC_REG expr = { + /* + * The ``:'' operator matches first expr against the second, + * which must be a regular expression. + */ + regex_t rp; + regmatch_t rm[2]; + int eval; + + /* compile regular expression */ + if ((eval = regcomp(&rp, $3, REG_BASIC)) != 0) { + char errbuf[256]; + (void)regerror(eval, &rp, errbuf, sizeof(errbuf)); + yyerror("%s", errbuf); + /* NOT REACHED */ + } + + /* compare string against pattern -- remember that patterns + are anchored to the beginning of the line */ + if (regexec(&rp, $1, 2, rm, 0) == 0 && rm[0].rm_so == 0) { + char *val; + if (rm[1].rm_so >= 0) { + (void) asprintf(&val, "%.*s", + (int) (rm[1].rm_eo - rm[1].rm_so), + $1 + rm[1].rm_so); + } else { + (void) asprintf(&val, "%d", + (int)(rm[0].rm_eo - rm[0].rm_so)); + } + if (val == NULL) + err(1, NULL); + $$ = val; + } else { + if (rp.re_nsub == 0) { + $$ = "0"; + } else { + $$ = ""; + } + } + + } + | expr ADD_SUB_OPERATOR expr = { + /* Returns the results of addition, subtraction */ + char *val; + int64_t res; + + res = perform_arith_op($1, $2, $3); + (void) asprintf(&val, "%lld", (long long int) res); + if (val == NULL) + err(1, NULL); + $$ = val; + } + + | expr MUL_DIV_MOD_OPERATOR expr = { + /* + * Returns the results of multiply, divide or remainder of + * numeric-valued arguments. + */ + char *val; + int64_t res; + + res = perform_arith_op($1, $2, $3); + (void) asprintf(&val, "%lld", (long long int) res); + if (val == NULL) + err(1, NULL); + $$ = val; + + } + | expr COMPARE expr = { + /* + * Returns the results of integer comparison if both arguments + * are integers; otherwise, returns the results of string + * comparison using the locale-specific collation sequence. + * The result of each comparison is 1 if the specified relation + * is true, or 0 if the relation is false. + */ + + int64_t l, r; + int res; + + res = 0; + + /* + * Slight hack to avoid differences in the compare code + * between string and numeric compare. + */ + if (is_integer($1) && is_integer($3)) { + /* numeric comparison */ + l = strtoll($1, NULL, 10); + r = strtoll($3, NULL, 10); + } else { + /* string comparison */ + l = strcoll($1, $3); + r = 0; + } + + switch($2[0]) { + case '=': /* equal */ + res = (l == r); + break; + case '>': /* greater or greater-equal */ + if ($2[1] == '=') + res = (l >= r); + else + res = (l > r); + break; + case '<': /* lower or lower-equal */ + if ($2[1] == '=') + res = (l <= r); + else + res = (l < r); + break; + case '!': /* not equal */ + /* the check if this is != was done in yylex() */ + res = (l != r); + } + + $$ = (res) ? "1" : "0"; + + } + | LEFT_PARENT expr RIGHT_PARENT { $$ = $2; } + | LENGTH expr { + /* + * Return length of 'expr' in bytes. + */ + char *ln; + + asprintf(&ln, "%ld", (long) strlen($2)); + if (ln == NULL) + err(1, NULL); + $$ = ln; + } + ; + +item: STRING + | ADD_SUB_OPERATOR + | MUL_DIV_MOD_OPERATOR + | COMPARE + | SPEC_OR + | SPEC_AND + | SPEC_REG + | LENGTH + ; +%% + +/* + * Returns 1 if the string is empty or contains only numeric zero. + */ +static int +is_zero_or_null(const char *str) +{ + char *endptr; + + return str[0] == '\0' + || ( strtoll(str, &endptr, 10) == 0LL + && endptr[0] == '\0'); +} + +/* + * Returns 1 if the string is an integer. + */ +static int +is_integer(const char *str) +{ + char *endptr; + + (void) strtoll(str, &endptr, 10); + /* note we treat empty string as valid number */ + return (endptr[0] == '\0'); +} + +static int64_t +perform_arith_op(const char *left, const char *op, const char *right) +{ + int64_t res, sign, l, r; + u_int64_t temp; + + res = 0; + + if (!is_integer(left)) { + yyerror("non-integer argument '%s'", left); + /* NOTREACHED */ + } + if (!is_integer(right)) { + yyerror("non-integer argument '%s'", right); + /* NOTREACHED */ + } + + errno = 0; + l = strtoll(left, NULL, 10); + if (errno == ERANGE) { + yyerror("value '%s' is %s is %lld", left, + (l > 0) ? "too big, maximum" : "too small, minimum", + (l > 0) ? LLONG_MAX : LLONG_MIN); + /* NOTREACHED */ + } + + errno = 0; + r = strtoll(right, NULL, 10); + if (errno == ERANGE) { + yyerror("value '%s' is %s is %lld", right, + (l > 0) ? "too big, maximum" : "too small, minimum", + (l > 0) ? LLONG_MAX : LLONG_MIN); + /* NOTREACHED */ + } + + switch(op[0]) { + case '+': + /* + * Do the op into an unsigned to avoid overflow and then cast + * back to check the resulting signage. + */ + temp = l + r; + res = (int64_t) temp; + /* very simplistic check for over-& underflow */ + if ((res < 0 && l > 0 && r > 0) + || (res > 0 && l < 0 && r < 0)) + yyerror("integer overflow or underflow occurred for " + "operation '%s %s %s'", left, op, right); + break; + case '-': + /* + * Do the op into an unsigned to avoid overflow and then cast + * back to check the resulting signage. + */ + temp = l - r; + res = (int64_t) temp; + /* very simplistic check for over-& underflow */ + if ((res < 0 && l > 0 && l > r) + || (res > 0 && l < 0 && l < r) ) + yyerror("integer overflow or underflow occurred for " + "operation '%s %s %s'", left, op, right); + break; + case '/': + if (r == 0) + yyerror("second argument to '%s' must not be zero", op); + res = l / r; + + break; + case '%': + if (r == 0) + yyerror("second argument to '%s' must not be zero", op); + res = l % r; + break; + case '*': + /* shortcut */ + if ((l == 0) || (r == 0)) { + res = 0; + break; + } + + sign = 1; + if (l < 0) + sign *= -1; + if (r < 0) + sign *= -1; + + res = l * r; + /* + * XXX: not the most portable but works on anything with 2's + * complement arithmetic. If the signs don't match or the + * result was 0 on 2's complement this overflowed. + */ + if ((res < 0 && sign > 0) || (res > 0 && sign < 0) || + (res == 0)) + yyerror("integer overflow or underflow occurred for " + "operation '%s %s %s'", left, op, right); + /* NOTREACHED */ + break; + } + return res; +} + +static const char *x = "|&=<>+-*/%:()"; +static const int x_token[] = { + SPEC_OR, SPEC_AND, COMPARE, COMPARE, COMPARE, ADD_SUB_OPERATOR, + ADD_SUB_OPERATOR, MUL_DIV_MOD_OPERATOR, MUL_DIV_MOD_OPERATOR, + MUL_DIV_MOD_OPERATOR, SPEC_REG, LEFT_PARENT, RIGHT_PARENT +}; + +static int handle_ddash = 1; + +int +yylex(void) +{ + const char *p = *av++; + int retval; + + if (!p) + retval = 0; + else if (p[1] == '\0') { + const char *w = strchr(x, p[0]); + if (w) { + retval = x_token[w-x]; + } else { + retval = STRING; + } + } else if (p[1] == '=' && p[2] == '\0' + && (p[0] == '>' || p[0] == '<' || p[0] == '!')) + retval = COMPARE; + else if (handle_ddash && p[0] == '-' && p[1] == '-' && p[2] == '\0') { + /* ignore "--" if passed as first argument and isn't followed + * by another STRING */ + retval = yylex(); + if (retval != STRING && retval != LEFT_PARENT + && retval != RIGHT_PARENT) { + /* is not followed by string or parenthesis, use as + * STRING */ + retval = STRING; + av--; /* was increased in call to yylex() above */ + p = "--"; + } else { + /* "--" is to be ignored */ + p = yylval; + } + } else if (strcmp(p, "length") == 0) + retval = LENGTH; + else + retval = STRING; + + handle_ddash = 0; + yylval = p; + + return retval; +} + +/* + * Print error message and exit with error 2 (syntax error). + */ +static __printflike(1, 2) void +yyerror(const char *fmt, ...) +{ + va_list arg; + + va_start(arg, fmt); + verrx(2, fmt, arg); + va_end(arg); +} + +int +main(int argc, const char * const *argv) +{ + setprogname(argv[0]); + (void)setlocale(LC_ALL, ""); + + if (argc == 1) { + (void)fprintf(stderr, "usage: %s expression\n", + getprogname()); + exit(2); + } + + av = argv + 1; + + exit(yyparse()); + /* NOTREACHED */ +} diff --git a/man/man1/Makefile b/man/man1/Makefile index 6578906ee..cbb2b6750 100644 --- a/man/man1/Makefile +++ b/man/man1/Makefile @@ -4,7 +4,7 @@ MAN= ash.1 at.1 banner.1 basename.1 \ cp.1 crc.1 crontab.1 dd.1 \ df.1 dhrystone.1 dosdir.1 dosread.1 doswrite.1 \ dumpcore.1 eject.1 \ - env.1 expand.1 expr.1 factor.1 \ + env.1 expand.1 factor.1 \ finger.1 flexdoc.1 fold.1 format.1 fortune.1 \ fsck.mfs.1 head.1 host.1 hostaddr.1 ifdef.1 \ isodir.1 isoinfo.1 isoread.1 kill.1 \ @@ -54,8 +54,6 @@ MLINKS += compress.1 uncompress.1 MLINKS += cp.1 mv.1 MLINKS += cp.1 ln.1 MLINKS += cp.1 cpdir.1 -MLINKS += expr.1 test.1 -MLINKS += expr.1 [.1 MLINKS += svc.1 ci.1 MLINKS += svc.1 co.1 diff --git a/man/man1/expr.1 b/man/man1/expr.1 deleted file mode 100644 index 9e04e73f3..000000000 --- a/man/man1/expr.1 +++ /dev/null @@ -1,245 +0,0 @@ -.TH EXPR 1 -.SH NAME \" Copyright (C) 1989 by Kenneth Almquist. -expr, test, [ \- evaluate expressions -.SH SYNOPSIS -.B expr -.I expression -.br -.B test -.I expression -.br -.B [ -.I expression -.B ] -.SH DESCRIPTION -.B Expr -evaluates the expression and prints the result. -.B Test -evaluates the expression without printing the result. -The ``['' -command is a synonym for -.BR test ; -when invoked under this name -the last argument to -.B expr -must be a ``]'', which is deleted and not considered part of the expression. -.PP -Three data types may occur in the -.IR expression : -string, integer, and boolean. -The rules for conversion are as follows: -.sp -.nr i 2 -.ta \nii -.in +\nii -.ti -\nii -\fIstring\fR\->\fIinteger\fR Done via -.BR atoi (3). -.ti -\nii -\fIinteger\fR\->\fIstring\fR Convert to decimal representation. -.ti -\nii -\fIstring\fR\->\fIboolean\fR "" \-> false, everything else to true. -.ti -\nii -\fIboolean\fR\->\fIstring\fR false \-> "", true \-> "true". -.ti -\nii -\fIinteger\fR\->\fIboolean\fR 0 \-> false, everything else to true. -.ti -\nii -\fIboolean\fR\->\fIinteger\fR false \-> 0, true \-> 1. -.in -\nii -.PP -Any argument to -.B expr -which is not a legal operator is treated as a string operand of type -.BR string . -.PP -As a special case, if -.I expression -is omitted, the result is false. -.PP -We now list the operators. The syntax -.sp -.ti +8 -\fIinteger\fB op \fIinteger\fR \-> \fIboolean\fB (3)\fR -.sp -means that \fBop\fR is a binary operator which takes operands of type -\fIinteger\fR and produces a result of type \fIboolean\fR. -The ``(3)'' means that the priority of \fBop\fR is 3. -Operands are automatically converted to the appropriate type. The type -\fIany\fR is used for operator that take operands of any type. -.nr p 1 -.de b -.TP 0.5i -\fI\\$1\fB \\$2 \fI\\$3\fR \-> \\fI\\$4\\fR (\\np) -.. -.de u -.TP 0.5i -\\$1 \fI\\$2\fR \-> \\fI\\$3\\fR (\\np) -.. -.b any \-o any any -Returns the value of the left hand operand if the left hand operand -would yield -.B true -if converted to type -.BR boolean , -and the value of the right hand operand otherwise. -The right hand operand is evaluated only if necessary. -``|'' is a synonym for ``\-o''. -.nr p \np+1 -.b any -a any any -Returns the value of the left hand operand if the left hand operand -would yield -.B false -if converted to type -.BR boolean , -and the value of the right hand operand otherwise. -The right hand operand is evaluated only if necessary. -``&'' is a synonym for ``\-a''. -.nr p \np+1 -.u ! boolean boolean -Returns true if the operand is false, and false if the operand is true. -.nr p \np+1 -.b string = string boolean -True if the two strings are equal. -.b string != string boolean -True if the two strings are not equal. -.b integer \-eq integer boolean -True if the two operands are equal. -.b integer \-ne integer boolean -True if the two operands are not equal. -.b integer \-gt integer boolean -True if the first operand is greater than the second one. -.b integer \-lt integer boolean -True if the first operand is less than the second one. -.b integer \-ge integer boolean -True if the first operand is greater than or equal to the second one. -.b integer \-le integer boolean -True if the first operand is less than or equal to the second one. -.nr p \np+1 -.b integer + integer integer -Add two integers. -.b integer \- integer integer -Subtract two integers. -.nr p \np+1 -.b integer * integer integer -Multiply two integers. ``*'' is special to the shell, so you generally -have to write this operator as ``\e*''. -.b integer / integer integer -Divide two integers. -.b integer % integer integer -Returns the remainder when the first operand is divided by the second one. -.nr p \np+1 -.b string : string "integer or string" -The second operand is interpreted as a regular expression (as in the -System V -.B ed -program). -This operator attempts to match part (or all) of the first operand -with the regular expression. The match must start at the beginning of -the first operand. -If the regular expression contains \e( \e) pairs, then the result -of this operator is the string which is matched by the regular expression -between these pairs, or the null string if no match occurred. Otherwise, -the result is the number of characters matched by the regular expression, -or zero if no no match occurred. -.nr p \np+1 -.u \-n string integer -Returns the number of characters in the string. -.u \-z string boolean -Returns true if the string contains zero characters. -.u \-t integer boolean -Returns true if the specified file descriptor is associated with a tty. -.PP -The remaining operators all deal with files. Except as noted, they return -false if the -specified file does not exist. The ones dealing with permission use -the effective user and group ids of the shell. -.u \-e string boolean -True the file exists. -.u \-r string boolean -True if you have read permission on the file. -.u \-w string boolean -True if you have write permission on the file. -.u \-x string boolean -True if you have execute permission on the file. -.u \-f string boolean -True if the file is a regular file. -.u \-d string boolean -True if the file is a directory. -.u \-c string boolean -True if the file is a character special file. -.u \-b string boolean -True if the file is a block special file. -.u \-p string boolean -True if the file is a named pipe (i.e. a fifo). -.u \-u string boolean -True if the file is setuid. -.u \-g string boolean -True if the file is setgid. -.u \-k string boolean -True if the file has the sticky bit set. -.u \-s string "integer or boolean" -Returns the size of the file, or 0 if the file does not exist. -.u \-h string boolean -True if the file is a symlink. This is the only file test operator that -does not follow symlinks, all others do. So ``\-d'' and ``\-h'' -are both true on a symlink pointing to a directory. -``\-L'' is a synonym for ``\-h''. -.SH "EXIT CODE" -0 if the result of -.I expression -would be -.B true -if the result were converted to -.BR boolean . -.br -1 if the result of -.I expression -would be -.B false -if the result were converted to -.BR boolean . -.br -2 if -.I expression -is syntactically incorrect. -.SH EXAMPLES -.TP 0.5i -filesize=`expr \-s file` -Sets the shell variable -.I filesize -to the size of -.IR file . -.TP 0.5i -if [ \-s file ]; then command; fi -Execute -.I command -if -.I file -exists and is not empty. -.TP 0.5i -x=`expr "$x" : '.\\{4\\}\\(.\\{0,3\\}\\)'` -Sets -.I x -to the substring of -.I x -beginning after the fourth character of -.I x -and continuing for three characters or until the end of the string, -whichever comes first. -.TP 0.5i -x=`expr X"$x" : X'.\\{4\\}\\(.\\{0,3\\}\\)'` -This example is the same as the previous one, but it uses a leading -``X'' to make things work when the value of -.I x -looks like an operator. -.SH BUGS -The relational operators of the System V -.B expr -command are not implemented. -.PP -Certain features of this version of -.B expr -are not present in System V, so care should be used when writing -portable code. -.SH COPYRIGHT -Kenneth Almquist. diff --git a/releasetools/nbsd_ports b/releasetools/nbsd_ports index e236e32f5..fd6a3c17d 100644 --- a/releasetools/nbsd_ports +++ b/releasetools/nbsd_ports @@ -10,6 +10,7 @@ 2011/08/27 12:55:09,bin/date 2012/10/17 12:00:00,bin/echo 2012/01/16 18:47:57,bin/ed +2012/10/17 12:00:00,bin/expr 2012/10/17 12:00:00,bin/Makefile 2012/10/17 12:00:00,bin/Makefile.inc 2008/07/20 00:52:40,bin/mkdir