I got the error "undefined reference to strrev".How could i remove this?

Answer 1

The strrev() function and some other string functions are only available in Turbo C/C++ which uses ANSI C and are not available in the standard C-GCC compiler.

Alternatively, you could write this function in your code:

#include<string.h>

char *strrev(char *str)
{
if (!str || ! *str)
return str;

int i = strlen(str) - 1, j = 0;

char ch;
while (i > j)
{
ch = str[i];
str[i] = str[j];
str[j] = ch;
i--;
j++;
}
return str;
}

//———————————
//or
//———————————

#include<string.h>

char *strrev(char *str)
{
char *p1, *p2;

if (! str || ! *str)
return str;
for (p1 = str, p2 = str + strlen(str) - 1; p2 > p1; ++p1, --p2)
{
*p1 ^= *p2;
*p2 ^= *p1;
*p1 ^= *p2;
}
return str;
}

Answer 2

Can you share your code?

Answer 3

I don't get the error /:

Answer 4

Thanks😊 Boub Fixer🇺🇬

Answer 5

thanks...Mohamed ELomari

Answer 6

i got error when i was compiling it on hackerearth .

Answer 7

i was coding on hackerearth terminal

Answer 8

here is an alternative to it:

#include<string.h>

char* strrev(char *str) {
if (! str || ! *str)
return str;
for (char *p1_str = str, *p2_str = str + strlen(str) - 1; p2_str > p1_str; ++p1_str, --p2_str) {
*p1_str ^= *p2_str;
*p2_str ^= *p1_str;
*p1_str ^= *p2_str;
}
return str;
}

Answer 9

yesValen.H. ~

Answer 10

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

int main() {
char s[50],b[50];
scanf("%s",s);
strcpy(b,s);
strrev(b);
if(strcmp(s,b)==0)
{
printf("palindrome");
}
else
{
printf("Not palindrome");
}
return 0;
}

Answer 11

strrev are not available in standard C-GCC compiler, you have to write the complete function that works same as an inbuilt function

Answer 12

this could also be because your devise must be old or webview is old version

Answer 13

What is the use of the condition
!str || !*str