Char wars

pwp.c: In function 'main':
pwp.c:43: warning: assignment from incompatible pointer type

A string declared as an array.
A string declared as a pointer.
A string constant copied in.
A string initialized at compile time.

...now for the char pointer stuff...
A str
A str
constant copied in.

constant cop

$g++ -Wall pwp.cpp -o pwp+.o
pwp.cpp: In function 'int main()':
pwp.cpp:20: warning: deprecated conversion from string constant to 'char*'
pwp.cpp:43: error: cannot convert 'char (*)[30]' to 'char*' in assignment

$nl pwp.c
1  /* playing_with_pointers.c - copied from strings.c

     2  Demonstrates printf, with no format specifier, prints strings initialized in
     3  any of four ways.
     4  Shows printf will recognize NULL as string terminator.
     5  Shows printf will work with a string location other than zero.
     6  Shows printf will work with both cases simultaneously.


     7  */
     8  #include <stdio.h>
     9  #include <string.h>

    10  int main()
    11  {
    12    /* Example 1 */
    13    char string1[] = "A string declared as an array.\n";

    14    /* Example 2 */
    15    char *string2 = "A string declared as a pointer.\n";

    16    /* Example 3 */
    17    char string3[30];
    18    char *cptr;

    19   /* Example 4 */

    20    char string4[40]="A string initialized at compile time.";
    21
    22    strcpy(string3, "A string constant copied in.\n");

    23    printf (string1);
    24    printf (string2);
    25    printf (string3);
    26    printf (string4);
    27    printf("\n");

    28  // Now start playing with char pointer.
    29    printf("\n...now for the char pointer stuff...\n");

    30    cptr=&string3[5];
    31    *cptr='\0';      //Place NULL where first lowercase i used to be.
    32    cptr=&string3;
    33    printf(string3);

    34    cptr=string3;    //Pass char pointer to printf()
    35    printf("\n%s", cptr );

    36  //Replace i and try printing from some other location in string.
    37    cptr=&string3[5]; *cptr='i'; cptr=&string3[9];
    38    printf("\n%s", cptr );

    39  //Now both cases together
    40    cptr=&string3[21]; *cptr='\0';   //Place NULL where second lowercase i used to be.
    41    cptr=&string3[9];   //printf() shoudl now display constant cop
    42    printf("\n%s\n", cptr);

    43    return 0;
    44  }

A string declared as an array.
A string declared as a pointer.
A string constant copied in.
A string initialized at compile time.

...now for the char pointer stuff...
Segmentation fault

$man gcc
No manual entry for gcc
See 'man 7 undocumented' for help when manual pages are not available.

/* playing_with_pointers.c - copied from strings.c

Demonstrates printf, with no format specifier, prints strings initialized in 
any of four ways.
Shows printf will recognize NULL as string terminator.
Shows printf will work with a string location other than zero.
Shows printf will work with both cases simultaneously.

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

int main()
{
  /* Example 1 */
  char string1[] = "A string declared as an array.\n";

  /* Example 2 */
  char *string2 = "A string declared as a pointer.\n";

  /* Example 3 */
  char string3[30];
  char *cptr;

 /* Example 4 */

  char string4[40]="A string initialized at compile time.";
  
  strcpy(string3, "A string constant copied in.\n");

  printf (string1);
  printf (string2);
  printf (string3);
  printf (string4);
  printf("\n");

// Now start playing with char pointer.
  printf("\n...now for the char pointer stuff...\n");

  cptr=string3 + 5;
  *cptr='\0';      //Place NULL where first lowercase i used to be.

  printf(string3);             //??? should display A stri ???

  cptr=string3;	   //Pass char pointer to printf()
  printf("\n%s", cptr );

//Replace i and try printing from some other location in string.
  cptr += 5; *cptr='i';
  cptr=string3 + 9;

  printf("\n%s", cptr );

//Now both cases together
  cptr -= 9; cptr += 21;

  *cptr='\0';   //Place NULL where second lowercase i used to be.

  cptr=string3 + 9;
  printf("\n%s\n", cptr);

  return 0;
}