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1 /*
2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3 %                                                                             %
4 %                                                                             %
5 %    SSS    CCC  RRRR   III  PPPP  TTTTT    TTTTT  OOO   K  K  EEEE  N   N    %
6 %   S      C     R   R   I   P   P   T        T   O   O  K K   E     NN  N    %
7 %    SSS   C     RRRR    I   PPPP    T        T   O   O  KK    EEE   N N N    %
8 %       S  C     R R     I   P       T        T   O   O  K K   E     N  NN    %
9 %   SSSS    CCC  R  RR  III  P       T        T    OOO   K  K  EEEE  N   N    %
10 %                                                                             %
11 %                    Tokenize Magick Script into Options                      %
12 %                                                                             %
13 %                             Dragon Computing                                %
14 %                             Anthony Thyssen                                 %
15 %                               January 2012                                  %
16 %                                                                             %
17 %                                                                             %
18 %  Copyright 1999-2016 ImageMagick Studio LLC, a non-profit organization      %
19 %  dedicated to making software imaging solutions freely available.           %
20 %                                                                             %
21 %  You may not use this file except in compliance with the License.  You may  %
22 %  obtain a copy of the License at                                            %
23 %                                                                             %
24 %    http://www.imagemagick.org/script/license.php                            %
25 %                                                                             %
26 %  Unless required by applicable law or agreed to in writing, software        %
27 %  distributed under the License is distributed on an "AS IS" BASIS,          %
28 %  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
29 %  See the License for the specific language governing permissions and        %
30 %  limitations under the License.                                             %
31 %                                                                             %
32 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
33 %
34 %  Read a stream of characters and return tokens one at a time.
35 %
36 %  The input stream is dived into individual 'tokens' (representing 'words' or
37 %  'options'), in a way that is as close to a UNIX shell, as is feasable.
38 %  Only shell variable, and command substitutions will not be performed.
39 %  Tokens can be any length.
40 %
41 %  The main function call is GetScriptToken() (see below) whcih returns one
42 %  and only one token at a time.  The other functions provide support to this
43 %  function, opening scripts, and seting up the required structures.
44 %
45 %  More specifically...
46 %
47 %  Tokens are white space separated, and may be quoted, or even partially
48 %  quoted by either single or double quotes, or the use of backslashes,
49 %  or any mix of the three.
50 %
51 %  For example:    This\ is' a 'single" token"
52 %
53 %  A token is returned immediatally the end of token is found. That is as soon
54 %  as a unquoted white-space or EOF condition has been found.  That is to say
55 %  the file stream is parsed purely character-by-character, regardless any
56 %  buffering constraints set by the system.  It is not parsed line-by-line.
57 %
58 %  The function will return 'MagickTrue' if a valid token was found, while
59 %  the token status will be set accordingally to 'OK' or 'EOF', according to
60 %  the cause of the end of token.  The token may be an empty string if the
61 %  input was a quoted empty string.  Other error conditions return a value of
62 %  MagickFalse, indicating any token found but was incomplete due to some
63 %  error condition.
64 %
65 %  Single quotes will preserve all characters including backslashes. Double
66 %  quotes will also preserve backslashes unless escaping a double quote,
67 %  or another backslashes.  Other shell meta-characters are not treated as
68 %  special by this tokenizer.
69 %
70 %  For example Quoting the quote chars:
71 %              \'  "'"       \"  '"'  "\""      \\  '\'  "\\"
72 %
73 %  Outside quotes, backslash characters will make spaces, tabs and quotes part
74 %  of a token returned. However a backslash at the end of a line (and outside
75 %  quotes) will cause the newline to be completely ignored (as per the shell
76 %  line continuation).
77 %
78 %  Comments start with a '#' character at the start of a new token, will be
79 %  completely ignored upto the end of line, regardless of any backslash at the
80 %  end of the line.  You can escape a comment '#', using quotes or backlsashes
81 %  just as you can in a shell.
82 %
83 %  The parser will accept both newlines, returns, or return-newlines to mark
84 %  the EOL. Though this is technically breaking (or perhaps adding to) the
85 %  'BASH' syntax that is being followed.
86 %
87 %
88 %  UNIX script Launcher...
89 %
90 %  The use of '#' comments allow normal UNIX 'scripting' to be used to call on
91 %  the "magick" command to parse the tokens from a file
92 %
93 %    #!/path/to/command/magick -script
94 %
95 %
96 %  UNIX 'env' command launcher...
97 %
98 %  If "magick" is renamed "magick-script" you can use a 'env' UNIX launcher
99 %
100 %    #!/usr/bin/env magick-script
101 %
102 %
103 %  Shell script launcher...
104 %
105 %  As a special case a ':' at the start of a line is also treated as a comment
106 %  This allows a magick script to ignore a line that can be parsed by the shell
107 %  and not by the magick script (tokenizer).  This allows for an alternative
108 %  script 'launcher' to be used for magick scripts.
109 %
110 %    #!/bin/sh
111 %    :; exec magick -script "$0" "$@"; exit 10
112 %    #
113 %    # The rest of the file is magick script
114 %    -read label:"This is a Magick Script!"
115 %    -write show: -exit
116 %
117 % Or with some shell pre/post processing...
118 %
119 %    #!/bin/sh
120 %    :; echo "This part is run in the shell, but ignored by Magick"
121 %    :; magick -script "$0" "$@"
122 %    :; echo "This is run after the "magick" script is finished!"
123 %    :; exit 10
124 %    #
125 %    # The rest of the file is magick script
126 %    -read label:"This is a Magick Script!"
127 %    -write show: -exit
128 %
129 %
130 %  DOS script launcher...
131 %
132 %  Similarly any '@' at the start of the line (outside of quotes) will also be
133 %  treated as comment. This allow you to create a DOS script launcher, to
134 %  allow a ".bat" DOS scripts to run as "magick" scripts instead.
135 %
136 %    @echo This line is DOS executed but ignored by Magick
137 %    @magick -script %~dpnx0 %*
138 %    @echo This line is processed after the Magick script is finished
139 %    @GOTO :EOF
140 %    #
141 %    # The rest of the file is magick script
142 %    -read label:"This is a Magick Script!"
143 %    -write show: -exit
144 %
145 % But this can also be used as a shell script launcher as well!
146 % Though is more restrictive and less free-form than using ':'.
147 %
148 %    #!/bin/sh
149 %    @() { exec magick -script "$@"; }
150 %    @ "$0" "$@"; exit
151 %    #
152 %    # The rest of the file is magick script
153 %    -read label:"This is a Magick Script!"
154 %    -write show: -exit
155 %
156 % Or even like this...
157 %
158 %    #!/bin/sh
159 %    @() { }
160 %    @; exec magick -script "$0" "$@"; exit
161 %    #
162 %    # The rest of the file is magick script
163 %    -read label:"This is a Magick Script!"
164 %    -write show: -exit
165 %
166 */
167 
168 /*
169   Include declarations.
170 
171   NOTE: Do not include if being compiled into the "test/script-token-test.c"
172   module, for low level token testing.
173 */
174 #ifndef SCRIPT_TOKEN_TESTING
175 #  include "MagickWand/studio.h"
176 #  include "MagickWand/MagickWand.h"
177 #  include "MagickWand/script-token.h"
178 #  include "MagickCore/string-private.h"
179 #  include "MagickCore/utility-private.h"
180 #endif
181 
182 /*
183 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
184 %                                                                             %
185 %                                                                             %
186 %                                                                             %
187 %   A c q u i r e S c r i p t T o k e n I n f o                               %
188 %                                                                             %
189 %                                                                             %
190 %                                                                             %
191 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
192 %
193 %  AcquireScriptTokenInfo() allocated, initializes and opens the given
194 %  file stream from which tokens are to be extracted.
195 %
196 %  The format of the AcquireScriptTokenInfo method is:
197 %
198 %     ScriptTokenInfo *AcquireScriptTokenInfo(char *filename)
199 %
200 %  A description of each parameter follows:
201 %
202 %    o filename   the filename to open  ("-" means stdin)
203 %
204 */
AcquireScriptTokenInfo(const char * filename)205 WandExport ScriptTokenInfo *AcquireScriptTokenInfo(const char *filename)
206 {
207   ScriptTokenInfo
208     *token_info;
209 
210   token_info=(ScriptTokenInfo *) AcquireMagickMemory(sizeof(*token_info));
211   if (token_info == (ScriptTokenInfo *) NULL)
212     return token_info;
213   (void) ResetMagickMemory(token_info,0,sizeof(*token_info));
214 
215   token_info->opened=MagickFalse;
216   if ( LocaleCompare(filename,"-") == 0 ) {
217     token_info->stream=stdin;
218     token_info->opened=MagickFalse;
219   }
220   else if ( LocaleNCompare(filename,"fd:",3) == 0 ) {
221     token_info->stream=fdopen(StringToLong(filename+3),"r");
222     token_info->opened=MagickFalse;
223   }
224   else {
225     token_info->stream=fopen_utf8(filename, "r");
226   }
227   if ( token_info->stream == (FILE *) NULL ) {
228     token_info=(ScriptTokenInfo *) RelinquishMagickMemory(token_info);
229     return(token_info);
230   }
231 
232   token_info->curr_line=1;
233   token_info->length=INITAL_TOKEN_LENGTH;
234   token_info->token=(char *) AcquireMagickMemory(token_info->length);
235 
236   token_info->status=(token_info->token != (char *) NULL)
237                       ? TokenStatusOK : TokenStatusMemoryFailed;
238   token_info->signature=MagickWandSignature;
239 
240   return token_info;
241 }
242 
243 /*
244 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
245 %                                                                             %
246 %                                                                             %
247 %                                                                             %
248 %   D e s t r o y S c r i p t T o k e n I n f o                               %
249 %                                                                             %
250 %                                                                             %
251 %                                                                             %
252 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
253 %
254 %  DestroyScriptTokenInfo() allocated, initializes and opens the given
255 %  file stream from which tokens are to be extracted.
256 %
257 %  The format of the DestroyScriptTokenInfo method is:
258 %
259 %     ScriptTokenInfo *DestroyScriptTokenInfo(ScriptTokenInfo *token_info)
260 %
261 %  A description of each parameter follows:
262 %
263 %    o token_info   The ScriptTokenInfo structure to be destroyed
264 %
265 */
DestroyScriptTokenInfo(ScriptTokenInfo * token_info)266 WandExport ScriptTokenInfo * DestroyScriptTokenInfo(ScriptTokenInfo *token_info)
267 {
268   assert(token_info != (ScriptTokenInfo *) NULL);
269   assert(token_info->signature == MagickWandSignature);
270 
271   if ( token_info->opened != MagickFalse )
272     fclose(token_info->stream);
273 
274   if (token_info->token != (char *) NULL )
275     token_info->token=(char *) RelinquishMagickMemory(token_info->token);
276   token_info=(ScriptTokenInfo *) RelinquishMagickMemory(token_info);
277   return(token_info);
278 }
279 
280 /*
281 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
282 %                                                                             %
283 %                                                                             %
284 %                                                                             %
285 %   G e t S c r i p t T o k e n                                               %
286 %                                                                             %
287 %                                                                             %
288 %                                                                             %
289 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
290 %
291 %  GetScriptToken() a fairly general, finite state token parser. That returns
292 %  tokens one at a time, as soon as posible.
293 %
294 %
295 %  The format of the GetScriptToken method is:
296 %
297 %     MagickBooleanType GetScriptToken(ScriptTokenInfo *token_info)
298 %
299 %  A description of each parameter follows:
300 %
301 %    o token_info    pointer to a structure holding token details
302 %
303 */
304 /* States of the parser */
305 #define IN_WHITE 0
306 #define IN_TOKEN 1
307 #define IN_QUOTE 2
308 #define IN_COMMENT 3
309 
310 /* Macro to read character from stream
311 
312    This also keeps track of the line and column counts.
313    The EOL is defined as either '\r\n', or '\r', or '\n'.
314    A '\r' on its own is converted into a '\n' to correctly handle
315    raw input, typically due to 'copy-n-paste' of text files.
316    But a '\r\n' sequence is left ASIS for string handling
317 */
318 #define GetChar(c) \
319 { \
320   c=fgetc(token_info->stream); \
321   token_info->curr_column++; \
322   if ( c == '\r' ) { \
323     c=fgetc(token_info->stream); \
324     ungetc(c,token_info->stream); \
325     c = (c!='\n')?'\n':'\r'; \
326   } \
327   if ( c == '\n' ) \
328     token_info->curr_line++, token_info->curr_column=0; \
329   if (c == EOF ) \
330     break; \
331   if ( (c>='\0' && c<'\a') || (c>'\r' && c<' ' && c!='\033') ) { \
332     token_info->status=TokenStatusBinary; \
333     break; \
334   } \
335 }
336 /* macro to collect the token characters */
337 #define SaveChar(c) \
338 { \
339   if ((size_t) offset >= (token_info->length-1)) { \
340     if ( token_info->length >= MagickPathExtent ) \
341       token_info->length += MagickPathExtent; \
342     else \
343       token_info->length *= 4; \
344     token_info->token = (char *) \
345          ResizeMagickMemory(token_info->token, token_info->length); \
346     if ( token_info->token == (char *) NULL ) { \
347       token_info->status=TokenStatusMemoryFailed; \
348       break; \
349     } \
350   } \
351   token_info->token[offset++]=(char) (c); \
352 }
353 
GetScriptToken(ScriptTokenInfo * token_info)354 WandExport MagickBooleanType GetScriptToken(ScriptTokenInfo *token_info)
355 {
356   int
357     quote,
358     c;
359 
360   int
361     state;
362 
363   ssize_t
364     offset;
365 
366   /* EOF - no more tokens! */
367   if (token_info == (ScriptTokenInfo *) NULL)
368     return(MagickFalse);
369   if (token_info->status != TokenStatusOK)
370     {
371       token_info->token[0]='\0';
372       return(MagickFalse);
373     }
374   state=IN_WHITE;
375   quote='\0';
376   offset=0;
377 DisableMSCWarning(4127)
378   while(1)
379 RestoreMSCWarning
380   {
381     /* get character */
382     GetChar(c);
383 
384     /* hash comment handling */
385     if ( state == IN_COMMENT ) {
386       if ( c == '\n' )
387         state=IN_WHITE;
388       continue;
389     }
390     /* comment lines start with '#' anywhere, or ':' or '@' at start of line */
391     if ( state == IN_WHITE )
392       if ( ( c == '#' ) ||
393            ( token_info->curr_column==1 && (c == ':' || c == '@' ) ) )
394         state=IN_COMMENT;
395     /* whitespace token separator character */
396     if (strchr(" \n\r\t",c) != (char *) NULL) {
397       switch (state) {
398         case IN_TOKEN:
399           token_info->token[offset]='\0';
400           return(MagickTrue);
401         case IN_QUOTE:
402           SaveChar(c);
403           break;
404       }
405       continue;
406     }
407     /* quote character */
408     if ( c=='\'' || c =='"' ) {
409       switch (state) {
410         case IN_WHITE:
411           token_info->token_line=token_info->curr_line;
412           token_info->token_column=token_info->curr_column;
413         case IN_TOKEN:
414           state=IN_QUOTE;
415           quote=c;
416           break;
417         case IN_QUOTE:
418           if (c == quote)
419             {
420               state=IN_TOKEN;
421               quote='\0';
422             }
423           else
424             SaveChar(c);
425           break;
426       }
427       continue;
428     }
429     /* escape char (preserve in quotes - unless escaping the same quote) */
430     if (c == '\\')
431       {
432         if ( state==IN_QUOTE && quote == '\'' ) {
433             SaveChar('\\');
434             continue;
435           }
436         GetChar(c);
437         if (c == '\n')
438           switch (state) {
439             case IN_COMMENT:
440               state=IN_WHITE;  /* end comment */
441             case IN_QUOTE:
442               if (quote != '"')
443                 break;         /* in double quotes only */
444             case IN_WHITE:
445             case IN_TOKEN:
446               continue;        /* line continuation - remove line feed */
447           }
448         switch (state) {
449           case IN_WHITE:
450             token_info->token_line=token_info->curr_line;
451             token_info->token_column=token_info->curr_column;
452             state=IN_TOKEN;
453             break;
454           case IN_QUOTE:
455             if (c != quote && c != '\\')
456               SaveChar('\\');
457             break;
458         }
459         SaveChar(c);
460         continue;
461       }
462     /* ordinary character */
463     switch (state) {
464       case IN_WHITE:
465         token_info->token_line=token_info->curr_line;
466         token_info->token_column=token_info->curr_column;
467         state=IN_TOKEN;
468       case IN_TOKEN:
469       case IN_QUOTE:
470         SaveChar(c);
471         break;
472       case IN_COMMENT:
473         break;
474     }
475   }
476   /* input stream has EOF or produced a fatal error */
477   token_info->token[offset]='\0';
478   if ( token_info->status != TokenStatusOK )
479     return(MagickFalse);  /* fatal condition - no valid token */
480   token_info->status = TokenStatusEOF;
481   if ( state == IN_QUOTE)
482     token_info->status = TokenStatusBadQuotes;
483   if ( state == IN_TOKEN)
484     return(MagickTrue);   /* token with EOF at end - no problem */
485   return(MagickFalse);    /* in white space or in quotes - invalid token */
486 }
487