Date: Thu, 5 May 2011 20:55:55 +0000 (UTC) From: Jilles Tjoelker <jilles@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r221513 - in head: bin/sh tools/regression/bin/sh/parser Message-ID: <201105052055.p45Ktt88015461@svn.freebsd.org>
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Author: jilles Date: Thu May 5 20:55:55 2011 New Revision: 221513 URL: http://svn.freebsd.org/changeset/base/221513 Log: sh: Add $'quoting' (C-style escape sequences). A string between $' and ' may contain backslash escape sequences similar to the ones in a C string constant (except that a single-quote must be escaped and a double-quote need not be). Details are in the sh(1) man page. This construct is useful to include unprintable characters, tabs and newlines in strings; while this can be done with a command substitution containing a printf command, that needs ugly workarounds if the result is to end with a newline as command substitution removes all trailing newlines. The construct may also be useful in future to describe unprintable characters without needing to write those characters themselves in 'set -x', 'export -p' and the like. The implementation attempts to comply to the proposal for the next issue of the POSIX specification. Because this construct is not in POSIX.1-2008, using it in scripts intended to be portable is unwise. Matching the minimal locale support in the rest of sh, the \u and \U sequences are currently not useful. Exp-run done by: pav (with some other sh(1) changes) Added: head/tools/regression/bin/sh/parser/dollar-quote1.0 (contents, props changed) head/tools/regression/bin/sh/parser/dollar-quote2.0 (contents, props changed) head/tools/regression/bin/sh/parser/dollar-quote3.0 (contents, props changed) head/tools/regression/bin/sh/parser/dollar-quote4.0 (contents, props changed) head/tools/regression/bin/sh/parser/dollar-quote5.0 (contents, props changed) head/tools/regression/bin/sh/parser/dollar-quote6.0 (contents, props changed) head/tools/regression/bin/sh/parser/dollar-quote7.0 (contents, props changed) head/tools/regression/bin/sh/parser/dollar-quote8.0 (contents, props changed) head/tools/regression/bin/sh/parser/dollar-quote9.0 (contents, props changed) Modified: head/bin/sh/mksyntax.c head/bin/sh/parser.c head/bin/sh/sh.1 Modified: head/bin/sh/mksyntax.c ============================================================================== --- head/bin/sh/mksyntax.c Thu May 5 19:49:27 2011 (r221512) +++ head/bin/sh/mksyntax.c Thu May 5 20:55:55 2011 (r221513) @@ -64,6 +64,7 @@ struct synclass synclass[] = { { "CWORD", "character is nothing special" }, { "CNL", "newline character" }, { "CBACK", "a backslash character" }, + { "CSBACK", "a backslash character in single quotes" }, { "CSQUOTE", "single quote" }, { "CDQUOTE", "double quote" }, { "CENDQUOTE", "a terminating quote" }, @@ -224,6 +225,7 @@ main(int argc __unused, char **argv __un init(); fputs("\n/* syntax table used when in single quotes */\n", cfile); add("\n", "CNL"); + add("\\", "CSBACK"); add("'", "CENDQUOTE"); /* ':/' for tilde expansion, '-' for [a\-x] pattern ranges */ add("!*?[=~:/-", "CCTL"); Modified: head/bin/sh/parser.c ============================================================================== --- head/bin/sh/parser.c Thu May 5 19:49:27 2011 (r221512) +++ head/bin/sh/parser.c Thu May 5 20:55:55 2011 (r221513) @@ -1127,6 +1127,127 @@ done: /* + * Called to parse a backslash escape sequence inside $'...'. + * The backslash has already been read. + */ +static char * +readcstyleesc(char *out) +{ + int c, v, i, n; + + c = pgetc(); + switch (c) { + case '\0': + synerror("Unterminated quoted string"); + case '\n': + plinno++; + if (doprompt) + setprompt(2); + else + setprompt(0); + return out; + case '\\': + case '\'': + case '"': + v = c; + break; + case 'a': v = '\a'; break; + case 'b': v = '\b'; break; + case 'e': v = '\033'; break; + case 'f': v = '\f'; break; + case 'n': v = '\n'; break; + case 'r': v = '\r'; break; + case 't': v = '\t'; break; + case 'v': v = '\v'; break; + case 'x': + v = 0; + for (;;) { + c = pgetc(); + if (c >= '0' && c <= '9') + v = (v << 4) + c - '0'; + else if (c >= 'A' && c <= 'F') + v = (v << 4) + c - 'A' + 10; + else if (c >= 'a' && c <= 'f') + v = (v << 4) + c - 'a' + 10; + else + break; + } + pungetc(); + break; + case '0': case '1': case '2': case '3': + case '4': case '5': case '6': case '7': + v = c - '0'; + c = pgetc(); + if (c >= '0' && c <= '7') { + v <<= 3; + v += c - '0'; + c = pgetc(); + if (c >= '0' && c <= '7') { + v <<= 3; + v += c - '0'; + } else + pungetc(); + } else + pungetc(); + break; + case 'c': + c = pgetc(); + if (c < 0x3f || c > 0x7a || c == 0x60) + synerror("Bad escape sequence"); + if (c == '\\' && pgetc() != '\\') + synerror("Bad escape sequence"); + if (c == '?') + v = 127; + else + v = c & 0x1f; + break; + case 'u': + case 'U': + n = c == 'U' ? 8 : 4; + v = 0; + for (i = 0; i < n; i++) { + c = pgetc(); + if (c >= '0' && c <= '9') + v = (v << 4) + c - '0'; + else if (c >= 'A' && c <= 'F') + v = (v << 4) + c - 'A' + 10; + else if (c >= 'a' && c <= 'f') + v = (v << 4) + c - 'a' + 10; + else + synerror("Bad escape sequence"); + } + if (v == 0 || (v >= 0xd800 && v <= 0xdfff)) + synerror("Bad escape sequence"); + /* We really need iconv here. */ + if (v > 127) + v = '?'; + break; + default: + synerror("Bad escape sequence"); + } + v = (char)v; + /* + * We can't handle NUL bytes. + * POSIX says we should skip till the closing quote. + */ + if (v == '\0') { + while ((c = pgetc()) != '\'') { + if (c == '\\') + c = pgetc(); + if (c == PEOF) + synerror("Unterminated quoted string"); + } + pungetc(); + return out; + } + if (SQSYNTAX[v] == CCTL) + USTPUTC(CTLESC, out); + USTPUTC(v, out); + return out; +} + + +/* * If eofmark is NULL, read a word or a redirection symbol. If eofmark * is not NULL, read a here document. In the latter case, eofmark is the * word which marks the end of the document and striptabs is true if @@ -1158,6 +1279,7 @@ readtoken1(int firstc, char const *initi struct tokenstate state_static[MAXNEST_static]; int maxnest = MAXNEST_static; struct tokenstate *state = state_static; + int sqiscstyle = 0; startlinno = plinno; quotef = 0; @@ -1188,6 +1310,12 @@ readtoken1(int firstc, char const *initi setprompt(0); c = pgetc(); goto loop; /* continue outer loop */ + case CSBACK: + if (sqiscstyle) { + out = readcstyleesc(out); + break; + } + /* FALLTHROUGH */ case CWORD: USTPUTC(c, out); break; @@ -1232,6 +1360,7 @@ readtoken1(int firstc, char const *initi case CSQUOTE: USTPUTC(CTLQUOTEMARK, out); state[level].syntax = SQSYNTAX; + sqiscstyle = 0; break; case CDQUOTE: USTPUTC(CTLQUOTEMARK, out); @@ -1450,11 +1579,7 @@ parsesub: { int c1; c = pgetc(); - if (c != '(' && c != '{' && (is_eof(c) || !is_name(c)) && - !is_special(c)) { - USTPUTC('$', out); - pungetc(); - } else if (c == '(') { /* $(command) or $((arith)) */ + if (c == '(') { /* $(command) or $((arith)) */ if (pgetc() == '(') { PARSEARITH(); } else { @@ -1465,7 +1590,7 @@ parsesub: { state[level].syntax == DQSYNTAX || state[level].syntax == ARISYNTAX); } - } else { + } else if (c == '{' || is_name(c) || is_special(c)) { USTPUTC(CTLVAR, out); typeloc = out - stackblock(); USTPUTC(VSNORMAL, out); @@ -1612,6 +1737,14 @@ varname: newvarnest++; } } + } else if (c == '\'' && state[level].syntax == BASESYNTAX) { + /* $'cstylequotes' */ + USTPUTC(CTLQUOTEMARK, out); + state[level].syntax = SQSYNTAX; + sqiscstyle = 1; + } else { + USTPUTC('$', out); + pungetc(); } goto parsesub_return; } Modified: head/bin/sh/sh.1 ============================================================================== --- head/bin/sh/sh.1 Thu May 5 19:49:27 2011 (r221512) +++ head/bin/sh/sh.1 Thu May 5 20:55:55 2011 (r221513) @@ -32,7 +32,7 @@ .\" from: @(#)sh.1 8.6 (Berkeley) 5/4/95 .\" $FreeBSD$ .\" -.Dd March 20, 2011 +.Dd May 5, 2011 .Dt SH 1 .Os .Sh NAME @@ -396,13 +396,82 @@ Quoting is used to remove the special me or words to the shell, such as operators, whitespace, keywords, or alias names. .Pp -There are three types of quoting: matched single quotes, +There are four types of quoting: matched single quotes, +dollar-single quotes, matched double quotes, and backslash. .Bl -tag -width indent .It Single Quotes Enclosing characters in single quotes preserves the literal meaning of all the characters (except single quotes, making it impossible to put single-quotes in a single-quoted string). +.It Dollar-Single Quotes +Enclosing characters between +.Li $' +and +.Li ' +preserves the literal meaning of all characters +except backslashes and single quotes. +A backslash introduces a C-style escape sequence: +.Bl -tag -width xUnnnnnnnn +.It \ea +Alert (ring the terminal bell) +.It \eb +Backspace +.It \ec Ns Ar c +The control character denoted by +.Li ^ Ns Ar c +in +.Xr stty 1 . +If +.Ar c +is a backslash, it must be doubled. +.It \ee +The ESC character +.Tn ( ASCII +0x1b) +.It \ef +Formfeed +.It \en +Newline +.It \er +Carriage return +.It \et +Horizontal tab +.It \ev +Vertical tab +.It \e\e +Literal backslash +.It \e\&' +Literal single-quote +.It \e\&" +Literal double-quote +.It \e Ns Ar nnn +The byte whose octal value is +.Ar nnn +(one to three digits) +.It \ex Ns Ar nn +The byte whose hexadecimal value is +.Ar nn +(one or more digits only the last two of which are used) +.It \eu Ns Ar nnnn +The Unicode code point +.Ar nnnn +(four hexadecimal digits) +.It \eU Ns Ar nnnnnnnn +The Unicode code point +.Ar nnnnnnnn +(eight hexadecimal digits) +.El +.Pp +The sequences for Unicode code points currently only provide useful results +for values below 128. +They reject code point 0 and UTF-16 surrogates. +.Pp +If an escape sequence would produce a byte with value 0, +that byte and the rest of the string until the matching single-quote +are ignored. +.Pp +Any other string starting with a backslash is an error. .It Double Quotes Enclosing characters within double quotes preserves the literal meaning of all characters except dollar sign Added: head/tools/regression/bin/sh/parser/dollar-quote1.0 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/tools/regression/bin/sh/parser/dollar-quote1.0 Thu May 5 20:55:55 2011 (r221513) @@ -0,0 +1,12 @@ +# $FreeBSD$ + +set -e + +[ $'hi' = hi ] +[ $'hi +there' = 'hi +there' ] +[ $'\"\'\\\a\b\f\t\v' = "\"'\\$(printf "\a\b\f\t\v")" ] +[ $'hi\nthere' = 'hi +there' ] +[ $'a\rb' = "$(printf "a\rb")" ] Added: head/tools/regression/bin/sh/parser/dollar-quote2.0 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/tools/regression/bin/sh/parser/dollar-quote2.0 Thu May 5 20:55:55 2011 (r221513) @@ -0,0 +1,5 @@ +# $FreeBSD$ + +# This depends on the ASCII character set. + +[ $'\e' = "$(printf "\033")" ] Added: head/tools/regression/bin/sh/parser/dollar-quote3.0 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/tools/regression/bin/sh/parser/dollar-quote3.0 Thu May 5 20:55:55 2011 (r221513) @@ -0,0 +1,22 @@ +# $FreeBSD$ + +unset LC_ALL +LC_CTYPE=en_US.ISO8859-1 +export LC_CTYPE + +e= +for i in 0 1 2 3; do + for j in 0 1 2 3 4 5 6 7; do + for k in 0 1 2 3 4 5 6 7; do + case $i$j$k in + 000) continue ;; + esac + e="$e\\$i$j$k" + done + done +done +ee=`printf "$e"` +[ "${#ee}" = 255 ] || echo length bad + +# Start a new shell so the locale change is picked up. +[ "$(${SH} -c "printf %s \$'$e'")" = "$ee" ] Added: head/tools/regression/bin/sh/parser/dollar-quote4.0 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/tools/regression/bin/sh/parser/dollar-quote4.0 Thu May 5 20:55:55 2011 (r221513) @@ -0,0 +1,19 @@ +# $FreeBSD$ + +unset LC_ALL +LC_CTYPE=en_US.ISO8859-1 +export LC_CTYPE + +e= +for i in 0 1 2 3 4 5 6 7 8 9 a b c d e f; do + for j in 0 1 2 3 4 5 6 7 8 9 a b c d e f; do + case $i$j in + 00) continue ;; + esac + e="$e\x$i$j" + done +done + +# Start a new shell so the locale change is picked up. +ee="$(${SH} -c "printf %s \$'$e'")" +[ "${#ee}" = 255 ] || echo length bad Added: head/tools/regression/bin/sh/parser/dollar-quote5.0 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/tools/regression/bin/sh/parser/dollar-quote5.0 Thu May 5 20:55:55 2011 (r221513) @@ -0,0 +1,12 @@ +# $FreeBSD$ + +# This depends on the ASCII character set. + +set -e + +[ $'\ca\cb\cc\cd\ce\cf\cg\ch\ci\cj\ck\cl\cm\cn\co\cp\cq\cr\cs\ct\cu\cv\cw\cx\cy\cz' = $'\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032' ] +[ $'\cA\cB\cC\cD\cE\cF\cG\cH\cI\cJ\cK\cL\cM\cN\cO\cP\cQ\cR\cS\cT\cU\cV\cW\cX\cY\cZ' = $'\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032' ] +[ $'\c[' = $'\033' ] +[ $'\c]' = $'\035' ] +[ $'\c^' = $'\036' ] +[ $'\c_' = $'\037' ] Added: head/tools/regression/bin/sh/parser/dollar-quote6.0 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/tools/regression/bin/sh/parser/dollar-quote6.0 Thu May 5 20:55:55 2011 (r221513) @@ -0,0 +1,5 @@ +# $FreeBSD$ + +# This depends on the ASCII character set. + +[ $'\c\\' = $'\034' ] Added: head/tools/regression/bin/sh/parser/dollar-quote7.0 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/tools/regression/bin/sh/parser/dollar-quote7.0 Thu May 5 20:55:55 2011 (r221513) @@ -0,0 +1,6 @@ +# $FreeBSD$ + +set -e + +[ $'\u0024\u0040\u0060' = '$@`' ] +[ $'\U00000024\U00000040\U00000060' = '$@`' ] Added: head/tools/regression/bin/sh/parser/dollar-quote8.0 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/tools/regression/bin/sh/parser/dollar-quote8.0 Thu May 5 20:55:55 2011 (r221513) @@ -0,0 +1,11 @@ +# $FreeBSD$ + +[ $'hello\0' = hello ] +[ $'hello\0world' = hello ] +[ $'hello\0'$'world' = helloworld ] +[ $'hello\000' = hello ] +[ $'hello\000world' = hello ] +[ $'hello\000'$'world' = helloworld ] +[ $'hello\x00' = hello ] +[ $'hello\x00world' = hello ] +[ $'hello\x00'$'world' = helloworld ] Added: head/tools/regression/bin/sh/parser/dollar-quote9.0 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/tools/regression/bin/sh/parser/dollar-quote9.0 Thu May 5 20:55:55 2011 (r221513) @@ -0,0 +1,8 @@ +# $FreeBSD$ + +# POSIX and C99 say D800-DFFF are undefined in a universal character name. +# We reject this but many other shells expand to something that looks like +# CESU-8. + +v=$( (eval ": \$'\uD800'") 2>&1 >/dev/null) +[ $? -ne 0 ] && [ -n "$v" ]
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