% This is TIE.W as of 17 Dec 92 %--------------------------------------------------------- % Copyright (c) 1989,1992 by THD/ITI. % All rights reserved. % % This program is distributed WITHOUT ANY WARRANTY, express or implied. % % Permission is granted to make and distribute verbatim copies of this % program provided that the copyright notice and this permission notice % are preserved on all copies. % % Permission is granted to copy and distribute modified versions of this % program under the conditions for verbatim copying, provided that the % entire resulting derived work is distributed under the terms of a % permission notice identical to this one. % % % Version 1.7 was built alike TIE.WEB Version 1.6 (89-01-27) % but used a command line interface only % Version 2.0 was revised to include optional tab expansion (89-02-01) % Version 2.1 deleted WEB relicts. (-js) (89-10-25) % Version 2.2 repaired replacing strategy (89-11-27) % Version 2.3 was slightly modified to be processed with the % cweb by Levy&Knuth. % also repaired loop control for end of changes test (92-09-24) % Version 2.4 included instead of when % used with ANSI-C (92-12-17) % See ChangeLog for further changes. % Here is TeX material that gets inserted after \input cwebmac \def\hang{\hangindent 3em\indent\ignorespaces} \font\mc=cmr9 \def\PASCAL{Pascal} \def\Cl{{\rm C}} \def\ASCII{{\mc ASCII}} \def\title{TIE} \def\topofcontents{\null\vfill \centerline{\titlefont The {\ttitlefont TIE} processor} \vskip 15pt \centerline{(CWEB Version 2.4)} \vfill} \def\botofcontents{ \null\vfill \item{$\copyright$}1989, 1992 by Technische Hochschule Darmstadt,\hfill\break Fachbereich Informatik, Institut f\"ur Theoretische Informatik\hfill\break All rights reserved.\hfill\break This program is distributed WITHOUT ANY WARRANTY, express or implied. \hfill\break Permission is granted to make and distribute verbatim copies of this program provided that the copyright notice and this permission notice are preserved on all copies. \hfill\break Permission is granted to copy and distribute modified versions of this program under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. } @* Introduction. \noindent Whenever a programmer wants to change a given \.{WEB} or \.{CWEB} program (referred to as a \.{WEB} program throughout this program) because of system dependencies, she or he will create a new change file. In addition there may be a second change file to modify system independent modules of the program. But the \.{WEB} file cannot be tangled and weaved with more than one change file simultaneously. Therefore, we introduce the present program to merge a \.{WEB} file and several change files producing a new \.{WEB} file. Since the input files are tied together, the program is called \.{TIE}. Furthermore, the program can be used to merge several change files giving a new single change file. This method seems to be more important because it doesn't modify the original source file. The use of \.{TIE} can be expanded to other programming languages since this processor only knows about the structure of change files and does not interpret the master file at all. The program \.{TIE} has to read lines from several input files to bring them in some special ordering. For this purpose an algorithm is used which looks a little bit complicated. But the method used only needs one buffer line for each input file. Thus the storage requirement of \.{TIE} does not depend on the input data. The program is written in \Cl\ and uses only few features of a particular environment that may need to be changed in other installations. E.g.\ it will not use the |enum| type declarations. The changes needed may refer to the access of the command line if this can be not supported by any \Cl\ compiler. The ``banner line'' defined here should be changed whenever \.{TIE} is modified. This program is put into the public domain. Nevertheless the copyright notice must not be replaced or modified. @d banner "This is TIE, CWEB Version 2.4." @d copyright "Copyright (c) 1989,1992 by THD/ITI. All rights reserved." @ The main outline of the program is given in the next section. This can be used more or less for any \Cl\ program. @c @@; @@; @@; @@; @@; @@; @@; @ Here are some macros for common programming idioms. @d incr(v) v+=1 /* increase a variable by unity */ @d decr(v) v-=1 /* decrease a variable by unity */ @d loop @+ while (1)@+ /* repeat over and over until a |break| happens */ @d do_nothing /* empty statement */ @f loop while @ Furthermore we include the additional types |boolean| and |string|. @d false 0 @d true 1 @= typedef int boolean; typedef char* string; @ The following parameters should be sufficient for most applications of \.{TIE}. @^system dependencies@> @= #define buf_size 512 /* maximum length of one input line */ #define max_file_index 9 /* we don't think that anyone needs more than 9 change files, but \dots\ just change it */ @ We introduce a history variable that allows us to set a return code if the operating system can use it. First we introduce the coded values for the history. This variable must be initialized. (We do this even if the value given may be the default for variables, just to document the need for the initial value.) @d spotless 0 @d troublesome 1 @d fatal 2 @= static int history=spotless; @* The character set. \noindent One of the main goals in the design of \.{TIE} has been to make it readily portable between a wide variety of computers. Yet \.{TIE} by its very nature must use a greater variety of characters than most computer programs deal with, and character encoding is one of the areas in which existing machines differ most widely from each other. To resolve this problem, all input to \.{TIE} is converted to an internal seven-bit code that is essentially standard \ASCII{}, the ``American Standard Code for Information Interchange.'' The conversion is done immediately when each character is read in. Conversely, characters are converted from \ASCII{} to the user's external representation just before they are output. But the algorithm is prepared for the usage of eight-bit data. \noindent Here is a table of the standard visible \ASCII{} codes: $$\def\:{\char\count255\global\advance\count255 by 1} \count255='40 \vbox{ \hbox{\hbox to 40pt{\it\hfill0\/\hfill}% \hbox to 40pt{\it\hfill1\/\hfill}% \hbox to 40pt{\it\hfill2\/\hfill}% \hbox to 40pt{\it\hfill3\/\hfill}% \hbox to 40pt{\it\hfill4\/\hfill}% \hbox to 40pt{\it\hfill5\/\hfill}% \hbox to 40pt{\it\hfill6\/\hfill}% \hbox to 40pt{\it\hfill7\/\hfill}} \vskip 4pt \hrule \def\^{\vrule height 10.5pt depth 4.5pt} \halign{\hbox to 0pt{\hskip -24pt\O{#0}\hfill}&\^ \hbox to 40pt{\tt\hfill#\hfill\^}& &\hbox to 40pt{\tt\hfill#\hfill\^}\cr 04&\:&\:&\:&\:&\:&\:&\:&\:\cr\noalign{\hrule} 05&\:&\:&\:&\:&\:&\:&\:&\:\cr\noalign{\hrule} 06&\:&\:&\:&\:&\:&\:&\:&\:\cr\noalign{\hrule} 07&\:&\:&\:&\:&\:&\:&\:&\:\cr\noalign{\hrule} 10&\:&\:&\:&\:&\:&\:&\:&\:\cr\noalign{\hrule} 11&\:&\:&\:&\:&\:&\:&\:&\:\cr\noalign{\hrule} 12&\:&\:&\:&\:&\:&\:&\:&\:\cr\noalign{\hrule} 13&\:&\:&\:&\:&\:&\:&\:&\:\cr\noalign{\hrule} 14&\:&\:&\:&\:&\:&\:&\:&\:\cr\noalign{\hrule} 15&\:&\:&\:&\:&\:&\:&\:&\:\cr\noalign{\hrule} 16&\:&\:&\:&\:&\:&\:&\:&\:\cr\noalign{\hrule} 17&\:&\:&\:&\:&\:&\:&\:\cr} \hrule width 280pt}$$ (Actually, of course, code |040| is an invisible blank space.) Code |0136| was once an upward arrow (\.{\char'13}), and code |0137| was once a left arrow (\.^^X), in olden times when the first draft of ASCII code was prepared; but \.{TIE} works with today's standard ASCII in which those codes represent circumflex and underline as shown. The maximum value used is also defined, it must be changed if an extended \ASCII{} is used. If the \Cl\ compiler is not able to process \&{unsigned char}'s, you should define |ASCII_Code| as \&{short}. @^system dependencies@> @= #define max_ASCII (@'~'+1) typedef unsigned char ASCII_Code; /* eight-bit numbers, a subrange of the integers */ @ \Cl\ was first implemented on a machine that uses the \ASCII{} representation for characters. But to make it readily available also for other machines (big brother is watching?)\ we add a conversion that may be undone for most installations. \.{TIE} assumes that it is being used with a character set that contains at least the characters of standard \ASCII{} as listed above. In order to accommodate this difference, we shall use the name |text_char| to stand for the data type of the characters in the input and output files. We shall also assume that |text_char| consists of the elements |first_text_char| through |last_text_char|, inclusive. The following definitions should be adjusted if necessary. @^system dependencies@> @d first_text_char 0 /* ordinal number of the smallest element of |text_char|*/ @d last_text_char 255 /* ordinal number of the largest element of |text_char|*/ @= typedef unsigned char text_char; /* the data type of characters in text files */ typedef FILE* text_file; @ The \.{TIE} processor converts between \ASCII{} code and the user's external character set by means of arrays |xord| and |xchr| that are analogous to \PASCAL's |ord| and |chr| functions. The mapping may be disabled by changing the following macro definitions to just a cast. If your \Cl\ compiler does not support \&{unsigned char}'s, you should incorporate a binary and with |0xff|. @^system dependencies@> @d map_xchr(c) (text_char)(c) /* change this to |xchr[c]| on non \ASCII{} machines */ @d map_xord(c) (ASCII_Code)(c) /* change this to |xord[c]| on non \ASCII{} machines */ @= static ASCII_Code xord[last_text_char+1]; /* specifies conversion of input characters */ static text_char xchr[max_ASCII+1]; /* specifies conversion of output characters */ @ If we assume that every system using \.{WEB} is able to read and write the visible characters of standard \ASCII{} (although not necessarily using the \ASCII{} codes to represent them), the following assignment statements initialize most of the |xchr| array properly, without needing any system-dependent changes. For example, the statement |xchr[@'A']='A'| that appears in the present \.{WEB} file might be encoded in, say, {\mc EBCDIC} code on the external medium on which it resides, but \.{CTANGLE} will convert from this external code to \ASCII{} and back again. Therefore the assignment statement |xchr[65]='A'| will appear in the corresponding \Cl\ file, and \Cl\ will compile this statement so that |xchr[65]| receives the character \.A in the external code. Note that it would be quite incorrect to say |xchr[@'A']=@'A'|, because |@'A'| is a constant of type |int| not \&{char}, and because we have |@'A'==65| regardless of the external character set. @= xchr[@' ']=' '; xchr[@'!']='!'; xchr[@'\"']='\"'; xchr[@'#']='#';@/ xchr[@'$']='$'; xchr[@'%']='%'; xchr[@'&']='&'; xchr[@'\'']='\'';@/ xchr[@'(']='('; xchr[@')']=')'; xchr[@'*']='*'; xchr[@'+']='+';@/ xchr[@',']=','; xchr[@'-']='-'; xchr[@'.']='.'; xchr[@'/']='/';@/ xchr[@'0']='0'; xchr[@'1']='1'; xchr[@'2']='2'; xchr[@'3']='3';@/ xchr[@'4']='4'; xchr[@'5']='5'; xchr[@'6']='6'; xchr[@'7']='7';@/ xchr[@'8']='8'; xchr[@'9']='9'; xchr[@':']=':'; xchr[@';']=';';@/ xchr[@'<']='<'; xchr[@'=']='='; xchr[@'>']='>'; xchr[@'?']='?';@/ xchr[@'@@']='@@'; xchr[@'A']='A'; xchr[@'B']='B'; xchr[@'C']='C';@/ xchr[@'D']='D'; xchr[@'E']='E'; xchr[@'F']='F'; xchr[@'G']='G';@/ xchr[@'H']='H'; xchr[@'I']='I'; xchr[@'J']='J'; xchr[@'K']='K';@/ xchr[@'L']='L'; xchr[@'M']='M'; xchr[@'N']='N'; xchr[@'O']='O';@/ xchr[@'P']='P'; xchr[@'Q']='Q'; xchr[@'R']='R'; xchr[@'S']='S';@/ xchr[@'T']='T'; xchr[@'U']='U'; xchr[@'V']='V'; xchr[@'W']='W';@/ xchr[@'X']='X'; xchr[@'Y']='Y'; xchr[@'Z']='Z'; xchr[@'[']='[';@/ xchr[@'\\']='\\'; xchr[@']']=']'; xchr[@'^']='^'; xchr[@'_']='_';@/ xchr[@'`']='`'; xchr[@'a']='a'; xchr[@'b']='b'; xchr[@'c']='c';@/ xchr[@'d']='d'; xchr[@'e']='e'; xchr[@'f']='f'; xchr[@'g']='g';@/ xchr[@'h']='h'; xchr[@'i']='i'; xchr[@'j']='j'; xchr[@'k']='k';@/ xchr[@'l']='l'; xchr[@'m']='m'; xchr[@'n']='n'; xchr[@'o']='o';@/ xchr[@'p']='p'; xchr[@'q']='q'; xchr[@'r']='r'; xchr[@'s']='s';@/ xchr[@'t']='t'; xchr[@'u']='u'; xchr[@'v']='v'; xchr[@'w']='w';@/ xchr[@'x']='x'; xchr[@'y']='y'; xchr[@'z']='z'; xchr[@'{']='{';@/ xchr[@'|']='|'; xchr[@'}']='}'; xchr[@'~']='~';@/ xchr[0]=' '; xchr[0x7F]=' '; /* these \ASCII{} codes are not used */ @ Some of the \ASCII{} codes below |0x20| have been given a symbolic name in \.{TIE} because they are used with a special meaning. @d tab_mark @'\t' /* \ASCII{} code used as tab-skip */ @d nl_mark @'\n' /* \ASCII{} code used as line end marker */ @d form_feed @'\f' /* \ASCII{} code used as page eject */ @ When we initialize the |xord| array and the remaining parts of |xchr|, it will be convenient to make use of an index variable, |i|. @= int i; @ Here now is the system-dependent part of the character set. If \.{TIE} is being implemented on a garden-variety \Cl\ for which only standard \ASCII{} codes will appear in the input and output files, you don't need to make any changes here. @^system dependencies@> Changes to the present module will make \.{TIE} more friendly on computers that have an extended character set, so that one can type things like \.^^Z. If you have an extended set of characters that are easily incorporated into text files, you can assign codes arbitrarily here, giving an |xchr| equivalent to whatever characters the users of \.{TIE} are allowed to have in their input files, provided that unsuitable characters do not correspond to special codes like |tab_mark| that are listed above. @= for (i=1;i<@' ';xchr[i++]=' '); xchr[tab_mark]='\t'; xchr[form_feed]='\f'; xchr[nl_mark]='\n'; @ The following system-independent code makes the |xord| array contain a suitable inverse to the information in |xchr|. @= for ( i=first_text_char ; i<=last_text_char ; xord[i++]=@' ' ) do_nothing; for ( i=1 ; i<=@'~' ; i++ ) xord[xchr[i]] = i; @* Input and output. \noindent Output for the user is done by writing on file |term_out|, which is assumed to consist of characters of type \&{text\_char}. It should be linked to |stdout| usually. Terminal input is not needed in this version of \.{TIE}. |stdin| and |stdout| are predefined if we include the \.{stdio.h} definitions. Although I/O redirection for |stdout| is usually available you may lead output to another file if you change the definition of |term_out|. Also we define some macros for terminating an output line and writing strings to the user. @^system dependencies@> @d term_out stdout @d print(a) fprintf(term_out,"%s",a) /* `|print|' means write on the terminal */ @d print2(a,b) fprintf(term_out,a,b) /* same with two arguments */ @d print3(a,b,c) fprintf(term_out,a,b,c) /* same with three arguments */ @d print_c(v) fputc(v,term_out); /* print a single character */ @d new_line(v) fputc('\n',v) /* start new line */ @d term_new_line new_line(term_out) /* start new line of the terminal */ @d print_ln(v) {fprintf(term_out,"%s",v);term_new_line;} /* `|print|' and then start new line */ @d print2_ln(a,b) {print2(a,b);term_new_line;} /* same with two arguments */ @d print3_ln(a,b,c) {print3(a,b,c);term_new_line;} /* same with three arguments */ @d print_nl(v) {term_new_line; print(v);} /* print information starting on a new line */ @d print2_nl(a,b) {term_new_line; print2(a,b);} /* same for two arguments */ @= #include @ And we need dynamic memory allocation. This should cause no trouble in any \Cl\ program. @^system dependencies@> @= #ifdef __STDC__ #include #else #include #endif @ The |update_terminal| function is called when we want to make sure that everything we have output to the terminal so far has actually left the computer's internal buffers and been sent. @^system dependencies@> @d update_terminal fflush(term_out) /* empty the terminal output buffer */ @* Data structures. \noindent The multiple input files (master file and change files) are treated the same way. To organize the simultaneous usage of several input files, we introduce the data type \&{in\_file\_modes}. The mode |search| indicates that \.{TIE} searches for a match of the input line with any line of an input file in |reading| mode. |test| is used whenever a match is found and it has to be tested if the next input lines do match also. |reading| describes that the lines can be read without any check for matching other lines. |ignore| denotes that the file cannot be used. This may happen because an error has been detected or because the end of the file has been found. \leavevmode |file_types| is used to describe whether a file is a master file or a change file. The value |unknown| is added to this type to set an initial mode for the output file. This enables us to check whether any option was used to select the kind of output. (this would even be necessary if we would assume a default action for missing options.) @= #define search 0 #define test 1 #define reading 2 #define ignore 3 typedef int in_file_modes; /* should be |enum(search,test,reading,ignore)| */ #define unknown 0 #define master 1 #define chf 2 typedef int file_types; /* should be |enum(unknown,master,chf)| */ @ A variable of type |out_md_type| will tell us in what state the output change file is during processing. |normal| will be the state, when we did not yet start a change, |pre| will be set when we write the lines to be changes and |post| will indicate that the replacement lines are written. @= #define normal 0 #define pre 1 #define post 2 typedef int out_md_type; /* should be |enum(normal,pre,post)| */ @ Two more types will indicate variables used as an index into either the file buffer or the file table. @= typedef int buffer_index; /* |-1..buf_size| */ typedef int file_index; /* |-1..max_file_index+1| */ @ The following data structure joins all informations needed to use these input files. %`line' is a normal identifier throughout this program @f line dummy @= typedef struct _idsc{ string name_of_file; ASCII_Code buffer[buf_size]; in_file_modes mode; long line; file_types type_of_file; buffer_index limit; text_file the_file; } input_description; @ These data types are used in the global variable section. They refer to the files in action, the number of change files, the mode of operation and the current output state. @= static file_index actual_input,test_input,no_ch; static file_types prod_chf=unknown; static out_md_type out_mode; @ All input files (including the master file) are recorded in the following structure. Mostly the components are accessed through a local pointer variable. This corresponds to \PASCAL's \&{with}-statement and results in a one-time-computation of the index expression. @= static input_description *input_organization[max_file_index+1]; @* File I/O. \noindent The basic function |get_line| can be used to get a line from an input file. The line is stored in the |buffer| part of the descriptor. The components |limit| and |line| are updated. If the end of the file is reached |mode| is set to |ignore|. On some systems it might be useful to replace tab characters by a proper number of spaces since several editors used to create change files insert tab characters into a source file not under control of the user. So it might be a problem to create a matching change file. @^tab character expansion@> We define |get_line| to read a line from a file specified by the corresponding file descriptor. @= void get_line(i) file_index i; {register input_description *inp_desc=input_organization[i]; if (inp_desc->mode==ignore) return; if (feof(inp_desc->the_file)) @@; @@; } @ End of file is special if this file is the master file. Then we set the global flag variable |input_has_ended|. @= { inp_desc->mode=ignore; inp_desc->limit=-1; /* mark end-of-file */ if (inp_desc->type_of_file==master) input_has_ended=true; return; } @ This variable must be declared for global access. @= static boolean input_has_ended=false; @ Lines must fit into the buffer completely. We read all characters sequentially until an end of line is found (but do not forget to check for |EOF|!). Too long input lines will be truncated. This will result in a damaged output if they occur in the replacement part of a change file, or in an incomplerte check if the matching part is concerned. Tab character expansion might be done here. @^tab character expansion@> @= {int final_limit; /* used to delete trailing spaces */ int c; /* the actual character read */ @@; inp_desc->limit=final_limit=0; while (inp_desc->limitthe_file); @@; inp_desc->buffer[inp_desc->limit++]=c=map_xord(c); if (c==nl_mark) break; /* end of line found */ if (c!=@' ' && c!=tab_mark) final_limit=inp_desc->limit; } @@; inp_desc->limit=final_limit; } @ This section does what its name says. Every 100 lines in the master file we print a dot, every 500 lines the number of lines is shown. @= incr(inp_desc->line); if (inp_desc->type_of_file==master && inp_desc->line % 100==0) { if (inp_desc->line % 500 == 0) print2("%ld",inp_desc->line); else print_c('.'); update_terminal; } @ There may be incomplete lines of the editor used does not make sure that the last character before end of file is an end of line. In such a case we must process the final line. Of the current line is empty, we just can \&{return}. Note that this test must be done {\sl before} the character read is translated. @^system dependencies@> @= if (c==EOF) { if (inp_desc->limit<=0) { inp_desc->mode=ignore; inp_desc->limit=-1; /* mark end-of-file */ if (inp_desc->type_of_file==master) input_has_ended=true; return; } else { /* add end of line mark */ c=nl_mark; break; } } @ If the line is truncated we must skip the rest (and still watch for |EOF|!). @= if (c!=nl_mark) { err_print("! Input line too long")(i); @.Input line too long@> while ( (c=fgetc(inp_desc->the_file)) != EOF && map_xord(c) != nl_mark ) do_nothing; /* skip to end */ } @* Reporting errors to the user. \noindent There may be errors if a line in a given change file does not match a line in the master file or a replacement in a previous change file. Such errors are reported to the user by saying $$ \hbox{|err_print("! Error message")(file_no)|;} $$ where |file_no| is the number of the file which is concerned by the error. Please note that no trailing dot is supplied by the error message because it is appended by |err_print|. This function is implemented as a macro. It gives a message and an indication of the offending file. The actions to determine the error location are provided by a function called |err_loc|. @d error_loc(m) err_loc(m); history=troublesome; @+ } @d err_print(m) { @+ print_nl(m); error_loc @= void err_loc(i) /* prints location of error */ int i; { print3_ln(" (file %s, l.%ld).", input_organization[i]->name_of_file, input_organization[i]->line); } @ Non recoverable errors are handled by calling |fatal_error| that outputs a message and then calls `|jump_out|'. |err_print| will print the error message followed by an indication of where the error was spotted in the source files. |fatal_error| cannot state any files because the problem is usually to access these. @d fatal_error(m) { print(m); print_c('.'); history=fatal; term_new_line; jump_out(); } @ |jump_out| just cuts across all active procedure levels and jumps out of the program. It is used when no recovery from a particular error has been provided. The return code from this program should be regarded by the caller. @d jump_out() exit(1) @* Handling multiple change files. \noindent In the standard version we take the name of the files from the command line. It is assumed that filenames can be used as given in the command line without changes. First there are some sections to open all files. If a file is not accessible, the run will be aborted. Otherwise the name of the open file will be displayed. @= { out_file=fopen(out_name,"w"); if (out_file==NULL) { fatal_error("! Could not open/create output file"); @.Could not open/create output file@> } } @ The name of the file and the file desciptor are stored in global variables. @= static text_file out_file; static string out_name; @ For the master file we start just reading its first line into the buffer, if we could open it. @= { input_organization[0]->the_file= fopen(input_organization[0]->name_of_file,"r"); if (input_organization[0]->the_file==NULL) fatal_error("! Could not open master file"); @.Could not open master file@> print2("(%s)",input_organization[0]->name_of_file); term_new_line; input_organization[0]->type_of_file=master; get_line(0); } @ For the change files we must skip the comment part and see, whether we can find any change in it. This is done by |init_change_file|. @= {file_index i; i=1; while (ithe_file= fopen(input_organization[i]->name_of_file,"r"); if (input_organization[i]->the_file==NULL) fatal_error("!Could not open change file"); @.Could not open change file@> print2("(%s)",input_organization[i]->name_of_file); term_new_line; init_change_file(i,true); incr(i); } } @*Input/output organization. \noindent Here's a simple function that checks if two lines are different. @= boolean lines_dont_match(i,j) file_index i,j; { buffer_index k,lmt; if (input_organization[i]->limit != input_organization[j]->limit) return(true); lmt=input_organization[i]->limit; for ( k=0 ; kbuffer[k] != input_organization[j]->buffer[k]) return(true); return(false); } @ Function |init_change_file(i,b)| is used to ignore all lines of the input file with index |i| until the next change module is found. The boolean parameter |b| indicates whether we do not want to see \.{@@x} or \.{@@y} entries during our skip. @= void init_change_file(i,b) file_index i; boolean b; {register input_description *inp_desc=input_organization[i]; @@; @@; } @ While looking for a line that begins with \.{@@x} in the change file, we allow lines that begin with \.{@@}, as long as they don't begin with \.{@@y} or \.{@@z} (which would probably indicate that the change file is fouled up). @= loop@+ {ASCII_Code c; get_line(i); if (inp_desc->mode==ignore) return; if (inp_desc->limit<2) continue; if (inp_desc->buffer[0] != @'@@') continue; c=inp_desc->buffer[1]; if (c>=@'X' && c<=@'Z') c+=@'z'-@'Z'; /*lowercasify*/ if (c==@'x') break; if (c==@'y' || c==@'z') if (b) /* scanning for start of change */ err_print("! Where is the matching @@x?")(i); @.Where is the match...@> } @ Here we are looking at lines following the \.{@@x}. @= do{ get_line(i); if (inp_desc->mode==ignore) { err_print("! Change file ended after @@x")(i); @.Change file ended...@> return; } } while (inp_desc->limit<=0); @ The |put_line| function is used to write a line from input buffer |j| to the output file. @= void put_line(j) file_index j; {buffer_index i; /* index into the buffer */ buffer_index lmt; /* line length */ ASCII_Code *p; /* output pointer */ lmt=input_organization[j]->limit; p=input_organization[j]->buffer; for (i=0;i= boolean e_of_ch_module(i) file_index i; {register input_description *inp_desc=input_organization[i]; if (inp_desc->limit<0) { print_nl("! At the end of change file missing @@z "); @.At the end of change file...@> print2("%s",input_organization[i]->name_of_file); term_new_line; return(true); } else if (inp_desc->limit>=2) if (inp_desc->buffer[0]==@'@@' && (inp_desc->buffer[1]==@'Z' || inp_desc->buffer[1]==@'z')) return(true); return(false); } @ The function |e_of_ch_preamble| returns |true| if the input line from file |i| starts with \.{@@y}. @= boolean e_of_ch_preamble(i) file_index i; {register input_description *inp_desc=input_organization[i]; if (inp_desc->limit>=2 && inp_desc->buffer[0]==@'@@') if (inp_desc->buffer[1]==@'Y'||inp_desc->buffer[1]==@'y') return(true); return(false); } @ To process the input file the next section reads a line of the actual input file and updates the |input_organization| for all files with index |test_file| greater |actual_input|. @= {file_index test_file; @@; if (input_has_ended && actual_input==0) break; /* all done */ @@; @@; @@; } @ Any of the current change files may have reached the end of change. In such a case intermediate lines must be skipped and the next start of change is to be found. This may make a change file inactive if it reaches end of file. @= {register input_description *inp_desc; while (actual_input>0 && e_of_ch_module(actual_input)) { inp_desc=input_organization[actual_input]; if (inp_desc->type_of_file==master) { /* emergency exit, everything mixed up!*/ fatal_error("! This can't happen: change file is master file"); @.This can't happen...@> } inp_desc->mode=search; init_change_file(actual_input,true); while ((input_organization[actual_input]->mode!=reading && actual_input>0)) decr(actual_input); } } @ Now we will set |test_input| to the file that has another match for the current line. This depends on the state of the other change files. If no other file matches, |actual_input| refers to a line to write and |test_input| ist set to |none|. @d none (max_file_index+1) @= test_input=none; test_file=actual_input; while (test_input==none && test_filemode) { case search: if (lines_dont_match(actual_input,test_file)==false) { input_organization[test_file]->mode=test; test_input=test_file; } break; case test: if (lines_dont_match(actual_input, test_file)==true) { /* error, sections do not match */ input_organization[test_file]->mode=search; err_print("! Sections do not match")(actual_input); @.Sections do not match@> err_loc(test_file); init_change_file(test_file,false); } else test_input=test_file; break; case reading: do_nothing; /* this can't happen */ break; case ignore: do_nothing; /* nothing to do */ break; } } @ For the output we must distinguish whether we create a new change file or a new master file. The change file creation needs some closer inspection because we may be before a change, in the pattern part or in the replacement part. For a master file we have to write the line from the current actual input. @= if (prod_chf==chf) { loop @+ { @@; @@; @@; } } else if (test_input==none) put_line(actual_input); @ Check whether we have to start a change file entry. Without a match nothing must be done. @= if (out_mode==normal) { if (test_input!=none) { fputc(map_xchr(@'@@'),out_file); fputc(map_xchr(@'x'),out_file); new_line(out_file); out_mode=pre; } else break; } @ Check whether we have to start the replacement text. This is the case when we have no more matching line. Otherwise the master file source line must be copied to the change file. @= if (out_mode==pre) { if (test_input==none) { fputc(map_xchr(@'@@'),out_file); fputc(map_xchr(@'y'),out_file); new_line(out_file); out_mode=post; } else { if (input_organization[actual_input]->type_of_file==master) put_line(actual_input); break; } } @ Check whether an entry from a change file is complete. If the current change was a change for a change file in effect, then this change file line must be written. If the actual input has been reset to the master file we can finish this change. @= if (out_mode==post) { if (input_organization[actual_input]->type_of_file==chf) { if (test_input==none) put_line(actual_input); break; } else { fputc(map_xchr(@'@@'),out_file); fputc(map_xchr(@'z'),out_file); new_line(out_file); new_line(out_file); out_mode=normal; } } @ If we had a change, we must proceed in the actual file to be changed and in the change file in effect. @= get_line(actual_input); if (test_input!=none) { get_line(test_input); if (e_of_ch_preamble(test_input)==true) { get_line(test_input); /* update current changing file */ input_organization[test_input]->mode=reading; actual_input=test_input; test_input=none; } } @ To create the new output file we have to scan the whole master file and all changes in effect when it ends. At the very end it is wise to check for all changes to have completed--in case the last line of the master file was to be changed. @= actual_input=0; input_has_ended=false; while (input_has_ended==false||actual_input!=0) @@; if (out_mode==post) { /* last line has been changed */ fputc(map_xchr(@'@@'),out_file); fputc(map_xchr(@'z'),out_file); new_line(out_file); } @ At the end of the program, we will tell the user if the change file had a line that didn't match any relevant line in the master file or any of the change files. @= {file_index i; for (i=1;imode!=ignore) err_print("! Change file entry did not match")(i); @.Change file entry ...@> } } @ We want to tell the user about our command line options. This is done by the |usage()| function. It contains merely the necessary print statement and exits afterwards. @= void usage() { print("Usage: tie -[mc] outfile master changefile(s)"); term_new_line; jump_out(); } @ We must scan through the list of parameters, given in |argv|. The number is in |argc|. We must pay attention to the flag parameter. We need at least 5~parameters and can handle up to |max_file_index| change files. The names fo the file parameters will be inserted into the structure of |input_organization|. The first file is special. It indicates the output file. When we allow flags at any position, we must find out which name is for what purpose. The master file is already part of the |input_organization| structure (index~0). As long as the number of files found (counted in |no_ch|) is |-1| we have not yet found the output file name. @= {int act_arg; if ( argc < 5 || argc > max_file_index+4-1 ) usage(); no_ch = -1; /* fill this part of |input_organization| */ for ( act_arg=1 ; act_arg@; else @@; } if (no_ch<=0|| prod_chf==unknown) usage(); } @ The flag is about to determine the processing mode. We must make sure that this flag has not been set before. Further flags might be introduced to avoid/force overwriting of output files. Currently we just have to set the processing flag properly. @= if (prod_chf!=unknown) usage(); else switch (argv[act_arg][1]) { case 'c': case 'C': prod_chf=chf; break; case 'm': case 'M': prod_chf=master; break; default: usage(); } @ We have to distinguish whether this is the very first file name (known if |no_ch==(-1)|) or if the next element of |input_organization| must be filled. @= { if (no_ch==(-1)) { out_name=argv[act_arg]; } else { register input_description *inp_desc; inp_desc=(input_description *) malloc(sizeof(input_description)); if (inp_desc==NULL) fatal_error("! No memory for descriptor"); @.No memory for descriptor@> inp_desc->mode=search; inp_desc->line=0; inp_desc->type_of_file=chf; inp_desc->limit=0; inp_desc->name_of_file=argv[act_arg]; input_organization[no_ch]=inp_desc; } incr(no_ch); } @* The main program. \noindent Here is where \.{TIE} starts, and where it ends. @= main(argc,argv) int argc; string *argv; {{@@; @@; } print_ln(banner); /* print a ``banner line'' */ print_ln(copyright); /* include the copyright notice */ actual_input=0; out_mode=normal; @@; @@; @@; @@; @@; @@; @@; } @ We want to pass the |history| value to the operating system so that it can be used to govern whether or not other programs are started. Additionaly we report the history to the user, although this may not be ``{\mc UNIX}'' style---but we are in best companion: \.{WEB} and \TeX{} do the same. @^system dependencies@> @= {string msg; switch (history) { case spotless: msg="No errors were found"; break; case troublesome: msg="Pardon me, but I think I spotted something wrong."; break; case fatal: msg="That was a fatal error, my friend"; break; } /* there are no other cases */ print2_nl("(%s.)",msg); term_new_line; exit ( history == spotless ? 0 : 1 ); } @* System-dependent changes. \noindent This section should be replaced, if necessary, by changes to the program that are necessary to make \.{TIE} work at a particular installation. It is usually best to design your change file so that all changes to previous modules preserve the module numbering; then everybody's version will be consistent with the printed program. More extensive changes, which introduce new modules, can be inserted here; then only the index itself will get a new module number. @^system dependencies@> @* Index. \noindent Here is the cross-reference table for the \.{TIE} processor.