"Warning: assignment makes integer from pointer without a cast" using a char malloc

Question

I'm making a code to remove the file name and type from a path. However, i'm receiving warnings concerning the line where i change the content from a character. How could i get rid of the warning?

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

char *getPath(char *fullPath){
    char *aux;
    int a, b, c;    
    
    
    aux = malloc(50 * sizeof(char));        
    aux = fullPath;
    
    
    a = strlen(aux);    
    
    
    for(b=0; b<a; b++){
        if (aux[b] == '/'){
            c = b;
        }
    }
    
    
    for(c; c < a; c++){
///PROBLEM HERE
        aux[c] = "";                
    }   
///PROBLEM HERE 
    return aux;
}



int main(void) {
    
    char C[50];
    char *path, *filename;
    scanf("%s", C);
    
    path = getPath(C);
    
    printf("%s", path);
    
}

aux[c] is a single character yet you assign it a string, this is not possible — M.M
– M.M, Commented Jan 27, 2021 at 3:02
Felipe what do you think aux = malloc(50 * sizeof(char)); aux = fullPath; does? — chux
– chux, Commented Jan 27, 2021 at 3:02
also, why do you call malloc then immediately discard the result (by reassigning aux) ? — M.M
– M.M, Commented Jan 27, 2021 at 3:02
another problem is that c is used uninitialized if there was no / — M.M
– M.M, Commented Jan 27, 2021 at 3:03
You have a major memory leak — you throw away the pointer to the allocated memory when you assign aux = fullPath;. You should probably be using strcpy(), and using strlen(fullPath) + 1 rather than 50. — Jonathan Leffler
– Jonathan Leffler, Commented Jan 27, 2021 at 3:05

Robert · Accepted Answer · 2021-01-27 03:02:53Z

1

aux[c] = ""; // here "" is a char *

aux is a char *, therefore aux[c] is a char (not a string "")

aux[c] = '\0';

As written in the comments, there still have other mistakes in the rest of the code: for example aux value is erased.

answered Jan 27, 2021 at 3:02

Robert

2,81211 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Akari Oozora Over a year ago

I solved this malloc mistake, and changed the "" for ''. I didn't know that "" was for strings and '' for characters, thought it was the same.

user8243991 · Accepted Answer · 2021-01-27 16:09:22Z

Tried fixing the entire code.

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

bool getPath(char *const strippedPath, const int strippedPath_buflen,const char *const fullPath){
  int b=strlen(fullPath);
  for(;;){
    --b;
    if(b<0)
      return false;
    if('/'==fullPath[b])
      break;
  }
  if(strippedPath_buflen<b+1)
    return false;
  strncpy(strippedPath,fullPath,b);
  strippedPath[b]='\0';
  return true;
}

int main(void) {
  for(;;){
    char C[50]={};
    printf("> ");
    fflush(stdout);
    scanf("%s",C);
    if(0==strcmp("quit",C))
      break;
    char path[3+1]={'X','X','X','X'};
    if(getPath(path,4,C))
      printf("%s\n",path);
    else
      printf("err\n");
  }
  return 0;
}

> aaaa/b.txt
err
> aaa/b.txt
aaa
> a/c/b.txt
a/c
> aa/b.txt
aa
> a/b.txt
a
> a/
a
> /b.txt

> b.txt
err
> quit

Collectives™ on Stack Overflow

"Warning: assignment makes integer from pointer without a cast" using a char malloc

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related