Removing last character in C

Question

The program I am writing needs to remove an ampersand character if it is the last character of a string. For instance, if char* str contains "firefox&", then I need to remove the ampersand so that str contains "firefox". Does anyone know how to do this?

Answer 1

Every string in C ends with '\0'. So you need do this:

int size = strlen(my_str); //Total size of string
my_str[size-1] = '\0';

This way, you remove the last char.

Answer 2

To be on the safe side:

if (str != NULL)
{
    const unsigned int length = strlen(str);
    if ((length > 0) && (str[length-1] == '&')) str[length-1] = '\0';
}

Answer 3

Just for reference, the standard function strchr does just that. It effectively splits the string on a given set of characters. It works by substituting a character with 0x00

Example shamelessly stolen from: cplusplus.com

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

int main ()
{
  char str[] = "This is a firefox& string";
  char * pch;
  printf ("Looking for the '&' character in \"%s\"...\n",str);
  pch=strchr(str,'&');
  while (pch!=NULL)
  {
    printf ("found at %d\n",pch-str+1);
    pch=strchr(pch+1,'&');
  }
  return 0;
}

Answer 4

Check the last character and if it is '&', replace it with '\0' (null terminator):

int size = strlen(my_str);
if (str[size - 1] == '&')
    str[size - 1] = '\0';