```
%%writefile spn.l
%option noyywrap

%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_PATH_LEN 255
#define MAX_COMP_LEN 14

char output[MAX_PATH_LEN + 1] = "";  // Store the output output
int portable = 0;  // 1 if path starts with '/', 0 otherwise

void error(const char *message);
%}

%%

[ \t]+          { /* Ignore extra lead or trailing spaces */ }

^"/"            { portable = 1; strcpy(output, "/"); }

".." { 
    if (strlen(output) == 0 || strcmp(output, "/") == 0) {
        error("malformed pathname");
    }
    
    char *last_slash = strrchr(output, '/');
    if (last_slash != NULL) {
        *last_slash = '\0';  // Remove last component
        if (strlen(output) == 0) {
            strcpy(output, "/"); // Change to root if now empty
        }
    } else {
        error("malformed pathname");
    }
}
"/"+            { /* Ignore extra '/' */ }

"."             { /* Ignore '.' */ }

[a-zA-Z0-9.]+   { 
                    if (portable && strlen(yytext) > MAX_COMP_LEN) {
                        error("component too long");
                    }
                    if (!portable && strlen(output) + strlen(yytext) + 1 > MAX_PATH_LEN) {
                        error("pathname too long");
                    }
                    if (strlen(output) > 0 && output[strlen(output) - 1] != '/') {
                        strcat(output, "/");
                    }
                    strcat(output, yytext);
                }

[^a-zA-Z0-9./\n\r]+  { error("invalid character"); }

[\r\n]+        { 
                    if (strlen(output) > 0 && output[strlen(output) - 1] == '/') {
                        output[strlen(output) - 1] = '\0'; // trailing '/'
                    }

                    if (strlen(output) > 0) {
                        printf("%s", output);  // Print path without \n
                    }
                    
                    output[0] = '\0';
                    portable = 0; 

                    printf("%s", yytext);
                }

%%

void error(const char *message) {
    fprintf(stderr, "%s\n", message);
    exit(1);
}

int main(void) {
    yylex();  
    printf("\n");
    return 0;
}
```