c - How to reverse a string without using in-built and temporary variables -

this question has answer here:

• segmentation fault occurring when modifying string using pointers? 7 answers
• is possible write function can reverse string without using buffer string? [duplicate] 2 answers

reverse operations out temporary variable , in-built functions string reverse.

you can using xor logic this:

char* rev(char* str) {     int end = strlen(str) - 1;     int start = 0;      while (start < end)     {         str[start] ^= str[end];         str[end] ^= str[start];         str[start] ^= str[end];          ++start;         --end;     }      return str; }