fork(1) download
copy 
  1. #include <stdio.h>
  2. #include <ctype.h>
  3. #include <string.h>
  4.  
  5. typedef enum {
  6.     TOK_UNKNOWN,
  7.     TOK_OPERATOR
  8. } TokenType;
  9.  
  10. typedef struct {
  11.     TokenType type;
  12.     char lexeme[3];   
  13. } Token;
  14.  
  15. static int is_op_start(char c) {
  16.     return c=='!' || c=='=' || c=='<' || c=='>' || c=='+' || c=='-' || c=='*' || c=='/';
  17. }
  18.  
  19. Token getToken(const char *s, int *i) {
  20.     Token tok;
  21.     tok.type = TOK_UNKNOWN;
  22.     tok.lexeme[0] = '\0';
  23.  
  24.     while (s[*i] && isspace((unsigned char)s[*i])) (*i)++;
  25.  
  26.     char c = s[*i];
  27.     if (!c) {
  28.         tok.type = TOK_UNKNOWN;
  29.         return tok;
  30.     }
  31.  
  32.     if (c=='!' || c=='=' || c=='<' || c=='>') {
  33.         char c2 = s[*i+1];
  34.         if (c=='!' && c2=='=') { tok.type = TOK_OPERATOR; strcpy(tok.lexeme, "!="); *i += 2; return tok; }
  35.         if (c=='=' && c2=='=') { tok.type = TOK_OPERATOR; strcpy(tok.lexeme, "=="); *i += 2; return tok; }
  36.         if (c=='<' && c2=='=') { tok.type = TOK_OPERATOR; strcpy(tok.lexeme, "<="); *i += 2; return tok; }
  37.         if (c=='>' && c2=='=') { tok.type = TOK_OPERATOR; strcpy(tok.lexeme, ">="); *i += 2; return tok; }
  38.  
  39.         // If your lexer supports single-char versions of these:
  40.         if (c=='<' ) { tok.type = TOK_OPERATOR; strcpy(tok.lexeme, "<");  *i += 1; return tok; }
  41.         if (c=='>' ) { tok.type = TOK_OPERATOR; strcpy(tok.lexeme, ">");  *i += 1; return tok; }
  42.  
  43.  
  44.     }
  45.  
  46.  
  47.     if (c=='+' || c=='-' || c=='*' || c=='/') {
  48.         tok.type = TOK_OPERATOR;
  49.         tok.lexeme[0] = c;
  50.         tok.lexeme[1] = '\0';
  51.         *i += 1;
  52.         return tok;
  53.     }
  54.  
  55.     *i += 1;
  56.     return tok;
  57. }
  58.  
  59.  
  60.  
  61. int main() {
  62.     char input[1000];
  63.     int i = 0;
  64.  
  65.     printf("Enter a simple C code snippet: ");
  66.     fgets(input, sizeof(input), stdin);
  67.  
  68.     printf("\nTokens Found:\n");
  69.  
  70.     while (input[i] != '\0') {
  71.  
  72.         if (isspace(input[i])) {
  73.             i++;
  74.             continue;
  75.         }
  76.  
  77.         if (
  78.             (input[i] == '+' && input[i+1] == '=') ||
  79.             (input[i] == '-' && input[i+1] == '=') ||
  80.             (input[i] == '*' && input[i+1] == '=') ||
  81.             (input[i] == '/' && input[i+1] == '=') ||
  82.             (input[i] == '=' && input[i+1] == '=') ||
  83.             (input[i] == '!' && input[i+1] == '=') ||
  84.             (input[i] == '>' && input[i+1] == '=') ||
  85.             (input[i] == '<' && input[i+1] == '=')
  86.         ) {
  87.             printf("OPERATOR: %c%c\n", input[i], input[i+1]);
  88.             i += 2;
  89.         }
  90.  
  91.         else if (input[i] == '+' || input[i] == '-' ||
  92.                  input[i] == '*' || input[i] == '/' ||
  93.                  input[i] == '=' || input[i] == '>' ||
  94.                  input[i] == '<' || input[i] == '!') {
  95.             printf("OPERATOR: %c\n", input[i]);
  96.             i++;
  97.         }
  98.         else {
  99.             i++; 
  100.         }
  101.     }
  102.  
  103.     return 0;
  104. }
Success #stdin #stdout 0.01s 5320KB
comments (?)
stdin
copy 
a+=b
stdout
copy 
Enter a simple C code snippet: 
Tokens Found:
OPERATOR: +=
https://ideone.com/x4Tm2R
language:
C (gcc 8.3)
created:
21 hours 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!