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script-token.c
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% SSS CCC RRRR III PPPP TTTTT TTTTT OOO K K EEEE N N %
% S C R R I P P T T O O K K E NN N %
% SSS C RRRR I PPPP T T O O KK EEE N N N %
% S C R R I P T T O O K K E N NN %
% SSSS CCC R RR III P T T OOO K K EEEE N N %
% %
% Tokenize Magick Script into Options %
% %
% Dragon Computing %
% Anthony Thyssen %
% January 2012 %
% %
% %
% Copyright @ 1999 ImageMagick Studio LLC, a non-profit organization %
% dedicated to making software imaging solutions freely available. %
% %
% You may not use this file except in compliance with the License. You may %
% obtain a copy of the License at %
% %
% https://imagemagick.org/script/license.php %
% %
% Unless required by applicable law or agreed to in writing, software %
% distributed under the License is distributed on an "AS IS" BASIS, %
% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
% See the License for the specific language governing permissions and %
% limitations under the License. %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Read a stream of characters and return tokens one at a time.
%
% The input stream is divided into individual 'tokens' (representing 'words'
% or 'options'), in a way that is as close to a UNIX shell, as is feasible.
% Only shell variable, and command substitutions will not be performed.
% Tokens can be any length.
%
% The main function call is GetScriptToken() (see below) which returns one
% and only one token at a time. The other functions provide support to this
% function, opening scripts, and setting up the required structures.
%
% More specifically...
%
% Tokens are white space separated, and may be quoted, or even partially
% quoted by either single or double quotes, or the use of backslashes,
% or any mix of the three.
%
% For example: This\ is' a 'single" token"
%
% A token is returned immediately the end of token is found. That is as soon
% as a unquoted white-space or EOF condition has been found. That is to say
% the file stream is parsed purely character-by-character, regardless any
% buffering constraints set by the system. It is not parsed line-by-line.
%
% The function will return 'MagickTrue' if a valid token was found, while
% the token status will be set accordingly to 'OK' or 'EOF', according to
% the cause of the end of token. The token may be an empty string if the
% input was a quoted empty string. Other error conditions return a value of
% MagickFalse, indicating any token found but was incomplete due to some
% error condition.
%
% Single quotes will preserve all characters including backslashes. Double
% quotes will also preserve backslashes unless escaping a double quote,
% or another backslashes. Other shell meta-characters are not treated as
% special by this tokenizer.
%
% For example Quoting the quote chars:
% \' "'" \" '"' "\"" \\ '\' "\\"
%
% Outside quotes, backslash characters will make spaces, tabs and quotes part
% of a token returned. However a backslash at the end of a line (and outside
% quotes) will cause the newline to be completely ignored (as per the shell
% line continuation).
%
% Comments start with a '#' character at the start of a new token, will be
% completely ignored upto the end of line, regardless of any backslash at the
% end of the line. You can escape a comment '#', using quotes or backslashes
% just as you can in a shell.
%
% The parser will accept both newlines, returns, or return-newlines to mark
% the EOL. Though this is technically breaking (or perhaps adding to) the
% 'BASH' syntax that is being followed.
%
%
% UNIX script Launcher...
%
% The use of '#' comments allow normal UNIX 'scripting' to be used to call on
% the "magick" command to parse the tokens from a file
%
% #!/path/to/command/magick -script
%
%
% UNIX 'env' command launcher...
%
% If "magick" is renamed "magick-script" you can use a 'env' UNIX launcher
%
% #!/usr/bin/env magick-script
%
%
% Shell script launcher...
%
% As a special case a ':' at the start of a line is also treated as a comment
% This allows a magick script to ignore a line that can be parsed by the shell
% and not by the magick script (tokenizer). This allows for an alternative
% script 'launcher' to be used for magick scripts.
%
% #!/bin/sh
% :; exec magick -script "$0" "$@"; exit 10
% #
% # The rest of the file is magick script
% -read label:"This is a Magick Script!"
% -write show: -exit
%
% Or with some shell pre/post processing...
%
% #!/bin/sh
% :; echo "This part is run in the shell, but ignored by Magick"
% :; magick -script "$0" "$@"
% :; echo "This is run after the "magick" script is finished!"
% :; exit 10
% #
% # The rest of the file is magick script
% -read label:"This is a Magick Script!"
% -write show: -exit
%
%
% DOS script launcher...
%
% Similarly any '@' at the start of the line (outside of quotes) will also be
% treated as comment. This allow you to create a DOS script launcher, to
% allow a ".bat" DOS scripts to run as "magick" scripts instead.
%
% @echo This line is DOS executed but ignored by Magick
% @magick -script %~dpnx0 %*
% @echo This line is processed after the Magick script is finished
% @GOTO :EOF
% #
% # The rest of the file is magick script
% -read label:"This is a Magick Script!"
% -write show: -exit
%
% But this can also be used as a shell script launcher as well!
% Though is more restrictive and less free-form than using ':'.
%
% #!/bin/sh
% @() { exec magick -script "$@"; }
% @ "$0" "$@"; exit
% #
% # The rest of the file is magick script
% -read label:"This is a Magick Script!"
% -write show: -exit
%
% Or even like this...
%
% #!/bin/sh
% @() { }
% @; exec magick -script "$0" "$@"; exit
% #
% # The rest of the file is magick script
% -read label:"This is a Magick Script!"
% -write show: -exit
%
*/
␌
/*
Include declarations.
NOTE: Do not include if being compiled into the "test/script-token-test.c"
module, for low level token testing.
*/
#ifndef SCRIPT_TOKEN_TESTING
# include "MagickWand/studio.h"
# include "MagickWand/MagickWand.h"
# include "MagickWand/script-token.h"
# include "MagickCore/string-private.h"
# include "MagickCore/utility-private.h"
#endif
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% A c q u i r e S c r i p t T o k e n I n f o %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% AcquireScriptTokenInfo() allocated, initializes and opens the given
% file stream from which tokens are to be extracted.
%
% The format of the AcquireScriptTokenInfo method is:
%
% ScriptTokenInfo *AcquireScriptTokenInfo(char *filename)
%
% A description of each parameter follows:
%
% o filename the filename to open ("-" means stdin)
%
*/
WandExport ScriptTokenInfo *AcquireScriptTokenInfo(const char *filename)
{
ScriptTokenInfo
*token_info;
token_info=(ScriptTokenInfo *) AcquireMagickMemory(sizeof(*token_info));
if (token_info == (ScriptTokenInfo *) NULL)
return token_info;
(void) memset(token_info,0,sizeof(*token_info));
token_info->opened=MagickFalse;
if ( LocaleCompare(filename,"-") == 0 ) {
token_info->stream=stdin;
token_info->opened=MagickFalse;
}
else if ( LocaleNCompare(filename,"fd:",3) == 0 ) {
token_info->stream=fdopen(StringToLong(filename+3),"r");
token_info->opened=MagickFalse;
}
else {
token_info->stream=fopen_utf8(filename, "r");
}
if ( token_info->stream == (FILE *) NULL ) {
token_info=(ScriptTokenInfo *) RelinquishMagickMemory(token_info);
return(token_info);
}
token_info->curr_line=1;
token_info->length=INITAL_TOKEN_LENGTH;
token_info->token=(char *) AcquireQuantumMemory(1,token_info->length);
token_info->status=(token_info->token != (char *) NULL)
? TokenStatusOK : TokenStatusMemoryFailed;
token_info->signature=MagickWandSignature;
return token_info;
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% D e s t r o y S c r i p t T o k e n I n f o %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% DestroyScriptTokenInfo() allocated, initializes and opens the given
% file stream from which tokens are to be extracted.
%
% The format of the DestroyScriptTokenInfo method is:
%
% ScriptTokenInfo *DestroyScriptTokenInfo(ScriptTokenInfo *token_info)
%
% A description of each parameter follows:
%
% o token_info The ScriptTokenInfo structure to be destroyed
%
*/
WandExport ScriptTokenInfo * DestroyScriptTokenInfo(ScriptTokenInfo *token_info)
{
assert(token_info != (ScriptTokenInfo *) NULL);
assert(token_info->signature == MagickWandSignature);
if ( token_info->opened != MagickFalse )
fclose(token_info->stream);
if (token_info->token != (char *) NULL )
token_info->token=(char *) RelinquishMagickMemory(token_info->token);
token_info=(ScriptTokenInfo *) RelinquishMagickMemory(token_info);
return(token_info);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t S c r i p t T o k e n %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetScriptToken() a fairly general, finite state token parser. That returns
% tokens one at a time, as soon as possible.
%
%
% The format of the GetScriptToken method is:
%
% MagickBooleanType GetScriptToken(ScriptTokenInfo *token_info)
%
% A description of each parameter follows:
%
% o token_info pointer to a structure holding token details
%
*/
/* States of the parser */
#define IN_WHITE 0
#define IN_TOKEN 1
#define IN_QUOTE 2
#define IN_COMMENT 3
/* Macro to read character from stream
This also keeps track of the line and column counts.
The EOL is defined as either '\r\n', or '\r', or '\n'.
A '\r' on its own is converted into a '\n' to correctly handle
raw input, typically due to 'copy-n-paste' of text files.
But a '\r\n' sequence is left ASIS for string handling
*/
#define GetChar(c) \
{ \
c=fgetc(token_info->stream); \
token_info->curr_column++; \
if ( c == '\r' ) { \
c=fgetc(token_info->stream); \
ungetc(c,token_info->stream); \
c = (c!='\n')?'\n':'\r'; \
} \
if ( c == '\n' ) \
token_info->curr_line++, token_info->curr_column=0; \
if (c == EOF ) \
break; \
if ( (c>='\0' && c<'\a') || (c>'\r' && c<' ' && c!='\033') ) { \
token_info->status=TokenStatusBinary; \
break; \
} \
}
/* macro to collect the token characters */
#define SaveChar(c) \
{ \
if ((size_t) offset >= (token_info->length-1)) { \
if (token_info == (ScriptTokenInfo *) NULL) \
break; \
if ( token_info->length >= MagickPathExtent ) \
token_info->length += MagickPathExtent; \
else \
token_info->length *= 4; \
token_info->token=(char *) ResizeQuantumMemory(token_info->token, \
token_info->length,sizeof(*token_info->token)); \
if ( token_info->token == (char *) NULL ) { \
token_info->status=TokenStatusMemoryFailed; \
break; \
} \
} \
if ( token_info->token == (char *) NULL ) \
token_info->status=TokenStatusMemoryFailed; \
else \
token_info->token[offset++]=(char) (c); \
}
WandExport MagickBooleanType GetScriptToken(ScriptTokenInfo *token_info)
{
int
quote,
c;
int
state;
ssize_t
offset;
/* EOF - no more tokens! */
if (token_info == (ScriptTokenInfo *) NULL)
return(MagickFalse);
if (token_info->status != TokenStatusOK)
{
token_info->token[0]='\0';
return(MagickFalse);
}
state=IN_WHITE;
quote='\0';
offset=0;
DisableMSCWarning(4127)
while(1)
RestoreMSCWarning
{
/* get character */
GetChar(c);
/* hash comment handling */
if ( state == IN_COMMENT ) {
if ( c == '\n' )
state=IN_WHITE;
continue;
}
/* comment lines start with '#' anywhere, or ':' or '@' at start of line */
if ( state == IN_WHITE )
if ( ( c == '#' ) ||
( token_info->curr_column==1 && (c == ':' || c == '@' ) ) )
state=IN_COMMENT;
/* whitespace token separator character */
if (strchr(" \n\r\t",c) != (char *) NULL) {
switch (state) {
case IN_TOKEN:
token_info->token[offset]='\0';
return(MagickTrue);
case IN_QUOTE:
SaveChar(c);
break;
}
continue;
}
/* quote character */
if ( c=='\'' || c =='"' ) {
switch (state) {
case IN_WHITE:
token_info->token_line=token_info->curr_line;
token_info->token_column=token_info->curr_column;
magick_fallthrough;
case IN_TOKEN:
state=IN_QUOTE;
quote=c;
break;
case IN_QUOTE:
if (c == quote)
{
state=IN_TOKEN;
quote='\0';
}
else
SaveChar(c);
break;
}
continue;
}
/* escape char (preserve in quotes - unless escaping the same quote) */
if (c == '\\')
{
if ( state==IN_QUOTE && quote == '\'' ) {
SaveChar('\\');
continue;
}
GetChar(c);
if (c == '\n')
switch (state) {
case IN_COMMENT:
state=IN_WHITE; /* end comment */
magick_fallthrough;
case IN_QUOTE:
if (quote != '"')
break; /* in double quotes only */
magick_fallthrough;
case IN_WHITE:
case IN_TOKEN:
continue; /* line continuation - remove line feed */
}
switch (state) {
case IN_WHITE:
token_info->token_line=token_info->curr_line;
token_info->token_column=token_info->curr_column;
state=IN_TOKEN;
break;
case IN_QUOTE:
if (c != quote && c != '\\')
SaveChar('\\');
break;
}
SaveChar(c);
continue;
}
/* ordinary character */
switch (state) {
case IN_WHITE:
token_info->token_line=token_info->curr_line;
token_info->token_column=token_info->curr_column;
state=IN_TOKEN;
magick_fallthrough;
case IN_TOKEN:
case IN_QUOTE:
SaveChar(c);
break;
case IN_COMMENT:
break;
}
}
/* input stream has EOF or produced a fatal error */
token_info->token[offset]='\0';
if ( token_info->status != TokenStatusOK )
return(MagickFalse); /* fatal condition - no valid token */
token_info->status = TokenStatusEOF;
if ( state == IN_QUOTE)
token_info->status = TokenStatusBadQuotes;
if ( state == IN_TOKEN)
return(MagickTrue); /* token with EOF at end - no problem */
return(MagickFalse); /* in white space or in quotes - invalid token */
}
ScriptTokenInfo
Definition script-token.h:40