28ad180ab4
The code is inspired by NetBSD sh somewhat, but different because we
preserve the old Almquist/Bourne/Korn ability to have an unquoted part in a
quoted ${v+word}. For example, "${v-"*"}" expands to $v as a single field if
v is set, but generates filenames otherwise.
Note that this is the only place where we split text literally from the
script (the similar ${v=word} assigns to v and then expands $v). The parser
must now add additional markers to allow the expansion code to know whether
arbitrary characters in substitutions are quoted.
Example:
for i in ${$+a b c}; do echo $i; done
Exp-run done by: pav (with some other sh(1) changes)
84 lines
3.4 KiB
C
84 lines
3.4 KiB
C
/*-
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Kenneth Almquist.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)parser.h 8.3 (Berkeley) 5/4/95
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* $FreeBSD$
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*/
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/* control characters in argument strings */
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#define CTLESC '\201'
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#define CTLVAR '\202'
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#define CTLENDVAR '\203'
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#define CTLBACKQ '\204'
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#define CTLQUOTE 01 /* ored with CTLBACKQ code if in quotes */
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/* CTLBACKQ | CTLQUOTE == '\205' */
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#define CTLARI '\206'
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#define CTLENDARI '\207'
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#define CTLQUOTEMARK '\210'
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#define CTLQUOTEEND '\211' /* only for ${v+-...} */
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/* variable substitution byte (follows CTLVAR) */
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#define VSTYPE 0x0f /* type of variable substitution */
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#define VSNUL 0x10 /* colon--treat the empty string as unset */
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#define VSLINENO 0x20 /* expansion of $LINENO, the line number \
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follows immediately */
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#define VSQUOTE 0x80 /* inside double quotes--suppress splitting */
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/* values of VSTYPE field */
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#define VSNORMAL 0x1 /* normal variable: $var or ${var} */
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#define VSMINUS 0x2 /* ${var-text} */
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#define VSPLUS 0x3 /* ${var+text} */
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#define VSQUESTION 0x4 /* ${var?message} */
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#define VSASSIGN 0x5 /* ${var=text} */
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#define VSTRIMLEFT 0x6 /* ${var#pattern} */
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#define VSTRIMLEFTMAX 0x7 /* ${var##pattern} */
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#define VSTRIMRIGHT 0x8 /* ${var%pattern} */
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#define VSTRIMRIGHTMAX 0x9 /* ${var%%pattern} */
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#define VSLENGTH 0xa /* ${#var} */
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#define VSERROR 0xb /* Syntax error, issue when expanded */
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/*
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* NEOF is returned by parsecmd when it encounters an end of file. It
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* must be distinct from NULL, so we use the address of a variable that
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* happens to be handy.
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*/
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extern int tokpushback;
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#define NEOF ((union node *)&tokpushback)
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extern int whichprompt; /* 1 == PS1, 2 == PS2 */
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extern const char *const parsekwd[];
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union node *parsecmd(int);
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void fixredir(union node *, const char *, int);
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int goodname(const char *);
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char *getprompt(void *);
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