1 files changed, 64 insertions, 0 deletions
diff --git a/src/cmd/delatex.lx b/src/cmd/delatex.lx
new file mode 100644
index 00000000..063aa7dc
--- /dev/null
+++ b/src/cmd/delatex.lx
@@ -0,0 +1,64 @@
+/* Make this with:  lex delatex.lex;  cc lex.yy.c -ll -o delatex */
+L [A-Za-z]
+%Start Display Math Normal Tag
+%%
+<Normal>\'	{yyleng--; yymore(); /* ignore apostrophes */}
+<Normal>{L}+\\- {yyleng-=2; yymore(); /* ignore hyphens */}
+<Normal>[a-z]/[^A-Za-z] ; /* ignore single letter "words" */
+<Normal>[A-Z]+	; /* ignore words all in uppercase */
+<Normal>{L}+('{L}*)*{L}	{printf("%s\n",yytext); /* any other letter seq is a word */} 
+<Normal>"%".*	; /* ignore comments */
+<Normal>\\{L}+	; /* ignore other control sequences */
+<Normal>"\\begin{"	BEGIN Tag; /* ignore this and up to next "}" */
+<Normal>"\\bibitem{"	BEGIN Tag;
+<Normal>"\\bibliography{"	BEGIN Tag;
+<Normal>"\\bibstyle{"	BEGIN Tag;
+<Normal>"\\cite{"	BEGIN Tag;
+<Normal>"\\end{"		BEGIN Tag;
+<Normal>"\\include{"	BEGIN Tag;
+<Normal>"\\includeonly{"	BEGIN Tag;
+<Normal>"\\input{"	BEGIN Tag;
+<Normal>"\\label{"	BEGIN Tag;
+<Normal>"\\pageref{"	BEGIN Tag;
+<Normal>"\\ref{"		BEGIN Tag;
+<Tag>[^}]		; /* ignore things up to next "}" */
+<Tag>"}"		BEGIN Normal;
+<Normal>[0-9]+	; /* ignore numbers */
+<Normal>"\\("		BEGIN Math; /* begin latex math mode */
+<Math>"\\)"		BEGIN Normal; /* end latex math mode */
+<Math>.|\\[^)]|\n	; /* ignore anything else in latex math mode */
+<Normal>"\\["		BEGIN Display; /* now in Latex display mode */
+<Display>[^$]|\\[^\]]	; /* ignore most things in display math mode */
+<Display>"\\]"	BEGIN Normal; /* get out of Display math mode */
+<Normal>\\.	; /* ignore other single character control sequences */
+<Normal>\\\n	; /* more of the same */
+<Normal>\n|.	; /* ignore anything else, a character at a time */
+%%
+#include <stdio.h>
+#include <stdlib.h>
+
+int
+main(int argc, char **argv)
+{
+	int i;
+	
+	BEGIN Normal; /* Starts yylex off in the right state */
+	if (argc==1) {
+	    yyin = stdin;
+	    yylex();
+	    }
+	else for (i=1; i<argc; i++) {
+	    yyin = fopen(argv[i],"r");
+	    if (yyin==NULL) {
+		fprintf(stderr,"can't open %s\n",argv[i]);
+		exit(1);
+		}
+	    yylex();
+	    }
+	exit(0);
+}
+int
+yywrap(void)
+{
+	return 1;
+}