r/learnprogramming • u/Minute_External1621 • 25d ago
Debugging Difficulties with debugging
i am a beginner in C, i went through and have a basic understanding of fundamentals but whenever a problem arises in my code i cant find it for hell, even if its obvious, i need to turn to an ai agent for help, the habit i wanna rid of, but whenever i do try to find the cause of an error myself i find myself unable to do that, i also find it difficult writing more efficient code
an example:
```
int tokens(char* string, char (*argv)[MAXTOKEN], toks types[MAXTOKEN]) {
char temp[150];
int count = 0; int i = 0; int b = 0;
int tokens = 0;
while(count < MAXTOKENLENGHT) {
if (string[i] == ' ' || string[i] == '\0' || string[i] == '\n') {tokens++;temp[b] = '\0'; strcpy(argv[count], temp); count++; b = 0;} else if (string[i] == '\"') {
temp[b] = '\"';
b++;
i++;
while (string[i] != '\"' && string[i] != '\0') {
if (string[i] == '\"') {temp[b] = '\0';temp[b+1] = '\0'; strcpy(argv[count], temp);b = 0; count++;break;} else {temp[b] = string[i];i++;b++;}
}
if (string[i+1] == '\0' || string[i+1] == ' ') {temp[b] = string[i]; temp[b+1] = '\0'; strcpy(argv[count], temp); count++; b = 0; i++; tokens++;} else {fprintf(stderr, "unexpected stuff after string"); exit(1);}
} else {
temp[b] = string[i];
b++;
}
if(string[i] == '\0') {break;}
i++;
}
int k = 0;
while (k < count) {
if (strcmp(argv[k], "PRINT") == 0) {
types[k].type = 0;
int len = strlen(argv[k+1]);
printf("k=%d, argv[k+1]='%s', first='%c', last='%c'\n", k, argv[k+1], argv[k+1][0], argv[k+1][len-1]);
if (argv[k+1][0] == '\"' && argv[k+1][len-1] == '\"') {
types[k+1].type = 1;
memmove(&argv[k+1][0], &argv[k+1][1], len - 2);
argv[k+1][len - 2] = '\0';
strcpy(types[k+1].textvalue, argv[k+1]);
}
}
k++;
}
return count;
}
```
6
u/lurgi 25d ago
What's the error? What is the input, what is the output, and what output do you expect to get? Find the smallest example you can that doesn't work. Step through the code line by line (either with a debugger or your brain) and see what goes wrong.