fork download 
  1. /* program name is lexp.l */
  2. %{
  3. /* program to recognize a C program */
  4. int COMMENT = 0;
  5. %}
  6.  
  7. identifier [a-zA-Z][a-zA-Z0-9]*
  8.  
  9. %%
  10.  
  11. #.* {
  12.     printf("\n%s is a PREPROCESSOR DIRECTIVE", yytext);
  13. }
  14.  
  15. (int|float|char|double|while|for|do|if|break|continue|void|switch|case|long|struct|const|typedef|return|else|goto) {
  16.     printf("\n\t%s is a KEYWORD", yytext);
  17. }
  18.  
  19. "/*" {
  20.     COMMENT = 1;
  21. }
  22.  
  23. "*/" {
  24.     COMMENT = 0;
  25. }
  26.  
  27. {identifier}\(.*\) {
  28.     if (!COMMENT)
  29.         printf("\n\nFUNCTION\n\t%s", yytext);
  30. }
  31.  
  32. \{ {
  33.     if (!COMMENT)
  34.         printf("\n BLOCK BEGINS");
  35. }
  36.  
  37. \} {
  38.     if (!COMMENT)
  39.         printf("\n BLOCK ENDS");
  40. }
  41.  
  42. {identifier}(\[[0-9]*\])? {
  43.     if (!COMMENT)
  44.         printf("\n %s IDENTIFIER", yytext);
  45. }
  46.  
  47. \".*\" {
  48.     if (!COMMENT)
  49.         printf("\n\t%s is a STRING", yytext);
  50. }
  51.  
  52. [0-9]+ {
  53.     if (!COMMENT)
  54.         printf("\n\t%s is a NUMBER", yytext);
  55. }
  56.  
  57. \)(\;)? {
  58.     if (!COMMENT)
  59.         printf("\n\t");
  60.     ECHO;
  61.     printf("\n");
  62. }
  63.  
  64. \( ECHO;
  65.  
  66. = {
  67.     if (!COMMENT)
  68.         printf("\n\t%s is an ASSIGNMENT OPERATOR", yytext);
  69. }
  70.  
  71. \<=|\>=|\<|==|\> {
  72.     if (!COMMENT)
  73.         printf("\n\t%s is a RELATIONAL OPERATOR", yytext);
  74. }
  75.  
  76. %%
  77.  
  78. int main(int argc, char **argv) {
  79.     if (argc > 1) {
  80.         FILE *file;
  81.         file = fopen(argv[1], "r");
  82.         if (!file) {
  83.             printf("could not open %s \n", argv[1]);
  84.             exit(0);
  85.         }
  86.         yyin = file;
  87.     }
  88.     yylex();
  89.     printf("\n\n");
  90.     return 0;
  91. }
  92.  
  93. int yywrap() {
  94.     return 0;
  95. }
  96.  
Success #stdin #stdout #stderr 0.03s 6948KB
comments (?)
stdin 
Standard input is empty
stdout 
Standard output is empty
stderr 
ERROR: /home/wFrNR6/prog:95:1: Syntax error: Unexpected end of file
ERROR: '$runtoplevel'/0: Undefined procedure: program/0
   Exception: (3) program ? EOF: exit
https://ideone.com/Zpflhy
language:
Prolog (swi 7.6.4)
created:
20 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!