Script started on Mon Sep 30 12:43:44 2024
mweeks@air:C_ch3$ cat array_example.c
/* 
   Array of 100 ints
   -MCW Sept. 2024
*/

#include <stdio.h>   

#define ARRAY_SIZE 100

int main () {

  int i;
  int myarray[ARRAY_SIZE] = { 23, 45, 56, 67 };

  for (i=0; i<ARRAY_SIZE; i++)
    printf("array[%d] is %d \n", i, myarray[i]);

  return 0;
}
mweeks@air:C_ch3$ gcc array_example.c
mweeks@air:C_ch3$ ./a.out
array[0] is 23 
array[1] is 45 
array[2] is 56 
array[3] is 67 
array[4] is 0 
array[5] is 0 
array[6] is 0 
array[7] is 0 
array[8] is 0 
array[9] is 0 
array[10] is 0 
array[11] is 0 
array[12] is 0 
array[13] is 0 
array[14] is 0 
array[15] is 0 
array[16] is 0 
array[17] is 0 
array[18] is 0 
array[19] is 0 
array[20] is 0 
array[21] is 0 
array[22] is 0 
array[23] is 0 
array[24] is 0 
array[25] is 0 
array[26] is 0 
array[27] is 0 
array[28] is 0 
array[29] is 0 
array[30] is 0 
array[31] is 0 
array[32] is 0 
array[33] is 0 
array[34] is 0 
array[35] is 0 
array[36] is 0 
array[37] is 0 
array[38] is 0 
array[39] is 0 
array[40] is 0 
array[41] is 0 
array[42] is 0 
array[43] is 0 
array[44] is 0 
array[45] is 0 
array[46] is 0 
array[47] is 0 
array[48] is 0 
array[49] is 0 
array[50] is 0 
array[51] is 0 
array[52] is 0 
array[53] is 0 
array[54] is 0 
array[55] is 0 
array[56] is 0 
array[57] is 0 
array[58] is 0 
array[59] is 0 
array[60] is 0 
array[61] is 0 
array[62] is 0 
array[63] is 0 
array[64] is 0 
array[65] is 0 
array[66] is 0 
array[67] is 0 
array[68] is 0 
array[69] is 0 
array[70] is 0 
array[71] is 0 
array[72] is 0 
array[73] is 0 
array[74] is 0 
array[75] is 0 
array[76] is 0 
array[77] is 0 
array[78] is 0 
array[79] is 0 
array[80] is 0 
array[81] is 0 
array[82] is 0 
array[83] is 0 
array[84] is 0 
array[85] is 0 
array[86] is 0 
array[87] is 0 
array[88] is 0 
array[89] is 0 
array[90] is 0 
array[91] is 0 
array[92] is 0 
array[93] is 0 
array[94] is 0 
array[95] is 0 
array[96] is 0 
array[97] is 0 
array[98] is 0 
array[99] is 0 
mweeks@air:C_ch3$ 
mweeks@air:C_ch3$ cd ..
mweeks@air:programs$ ls C_ch4
ls: C_ch4: No such file or directory
mweeks@air:programs$ cd C_ch3
mweeks@air:C_ch3$ echo "arithmetic ops + - * /" 
arithmetic ops + - * /
mweeks@air:C_ch3$ echo "arithmetic ops % (mod)"
arithmetic ops % (mod)
mweeks@air:C_ch3$ ls
Sept30_2024.log		bad_scanf_ex1.c		scanf_multiple.c
a.out			bitwise.c		scanf_p44.c
addfrac.c		expr.c			switch_example.c
array_example.c		rand_ex1.c		temp.c
bad_printfs.c		scanf_ex1.c
bad_printfs2.c		scanf_ex1.s
mweeks@air:C_ch3$ cp temp.c mod_example.c
mweeks@air:C_ch3$ vi mod_example.c 
mweeks@air:C_ch3$ gcc mod_example.c 
mweeks@air:C_ch3$ cat mod_example.c 
/* 
   mod example
   -MCW Sept. 2024
*/

#include <stdio.h>   

int main () {

  int number;

  printf("enter an int: "); 
  scanf("%d", &number);
  printf("You entered %d, and mod 100 it is %d\n", number, number % 100);


  return 0;
}
mweeks@air:C_ch3$ ./a.out
enter an int: 34
You entered 34, and mod 100 it is 34
mweeks@air:C_ch3$ ./a.out
enter an int: 103
You entered 103, and mod 100 it is 3
mweeks@air:C_ch3$ ./a.out
enter an int: 99
You entered 99, and mod 100 it is 99
mweeks@air:C_ch3$ ./a.out
enter an int: 100
You entered 100, and mod 100 it is 0
mweeks@air:C_ch3$ echo "operators ++ and --"
operators ++ and --
mweeks@air:C_ch3$ cp mod_example.c inc_dec_example.c
mweeks@air:C_ch3$ vi inc_dec_example.c 
mweeks@air:C_ch3$ gcc inc_dec_example.c 
inc_dec_example.c:14:71: warning: unsequenced modification and access to
      'number' [-Wunsequenced]
  ...entered %d, and ++ is %d and -- is %d\n", number, number++, number--);
                                               ~~~~~~        ^
1 warning generated.
mweeks@air:C_ch3$ vi inc_dec_example.c 
mweeks@air:C_ch3$ gcc inc_dec_example.c 
mweeks@air:C_ch3$ cat inc_dec_example.c 
/* 
   mod example
   -MCW Sept. 2024
*/

#include <stdio.h>   

int main () {

  int number;

  printf("enter an int: "); 
  scanf("%d", &number); 
  int num2 = number;
  int num3 = number;
  printf("You entered %d, and ++ is %d and -- is %d\n", number, num2++, num3--);


  return 0;
}
mweeks@air:C_ch3$ ./a.out
enter an int: 7
You entered 7, and ++ is 7 and -- is 7
mweeks@air:C_ch3$ vi inc_dec_example.c 
mweeks@air:C_ch3$ gcc inc_dec_example.c 
mweeks@air:C_ch3$ ./a.out
enter an int: 7
You entered 7, and ++ is 7 and -- is 7
after 8 and 6
You entered 7, and ++ is 8 and -- is 6
mweeks@air:C_ch3$ cat inc_dec_example.c 
/* 
   inc/dec example
   -MCW Sept. 2024
*/

#include <stdio.h>   

int main () {

  int number;

  printf("enter an int: "); 
  scanf("%d", &number); 
  int num2 = number;
  int num3 = number;
  printf("You entered %d, and ++ is %d and -- is %d\n", number, num2++, num3--);
  printf("after %d and %d\n", num2, num3);

  num2 = number;
  num3 = number;
  printf("You entered %d, and ++ is %d and -- is %d\n", number, ++num2, --num3);

  return 0;
}
mweeks@air:C_ch3$ 
mweeks@air:C_ch3$ 
mweeks@air:C_ch3$ echo "operators < > <= >= == !="
operators < > <= >= == !=
mweeks@air:C_ch3$ echo "precedence + - (unary)    +5   -3"
precedence + - (unary)    +5   -3
mweeks@air:C_ch3$ echo "precedence * / %"
precedence * / %
mweeks@air:C_ch3$ echo "precedence + - (binary)     2+5   1-3"
precedence + - (binary)     2+5   1-3
mweeks@air:C_ch3$ echo "1 - 3 * 2    1 - (6)    -5"
1 - 3 * 2    1 - (6)    -5
mweeks@air:C_ch3$ echo "(1 - 3) * 2"
(1 - 3) * 2
mweeks@air:C_ch3$ echo "  3 - 4 + 1"
  3 - 4 + 1
mweeks@air:C_ch3$ echo " 0 is false, but anything else is true"
 0 is false, but anything else is true
mweeks@air:C_ch3$ cd ../C_ch5
mweeks@air:C_ch5$ ls
bitcount.c	expr.c
mweeks@air:C_ch5$ echo "ch5: logical ops  && || ! "
ch5: logical ops  && || ! 
mweeks@air:C_ch5$ cat expr.c 
// expr1 : expr2 expr3
// Conditional operators
// "?" followed by ":"
//
// expr1? expr2:expr3;   // this means
// if expr1 is true then
//    expr2 
// else 
//   expr3


  for (i=0; i<n; i++) {
    printf("%6d %c",
      a[i], (i%10==9||i==(n-1))?'\n':' ');
  }

mweeks@air:C_ch5$ vi expr.c 
mweeks@air:C_ch5$ gcc expr.c 
mweeks@air:C_ch5$ cat expr.c 
// expr1 : expr2 expr3
// Conditional operators
// "?" followed by ":"
//
// expr1? expr2:expr3;   // this means
// if expr1 is true then
//    expr2 
// else 
//   expr3

#include <stdio.h>

#define n 6

int main() {
  int a[n] = {1, 2, 3, 4, 5, 6};
  int i;

  for (i=0; i<n; i++) {
    printf("%6d %c",
      a[i], (i%10==9||i==(n-1))?'\n':' ');
  }
  return 0;
}
mweeks@air:C_ch5$ echo "expr1 ? expr2:expr3"
expr1 ? expr2:expr3
mweeks@air:C_ch5$ ./a.out
     1       2       3       4       5       6 
mweeks@air:C_ch5$ vi expr.c 
mweeks@air:C_ch5$ ls -l ex*
-rw-r--r--  1 mweeks  staff  367 Sep 30 13:17 expr.c
-rw-r--r--  1 mweeks  staff  366 Sep 30 13:23 expr2.c
mweeks@air:C_ch5$ cat expr2.c 
// expr1 : expr2 expr3
// Conditional operators
// "?" followed by ":"
//
// expr1? expr2:expr3;   // this means
// if expr1 is true then
//    expr2 
// else 
//   expr3

#include <stdio.h>

#define n 6

int main() {
  int a[n] = {1, 2, 3, 4, 5, 6};
  int i;

  for (i=0; i<n; i++) {
    printf("%6d %c",
      a[i], (i%4==3||i==(n-1))?'\n':' ');
  }
  return 0;
}
mweeks@air:C_ch5$ gcc expr2.c
mweeks@air:C_ch5$ ./a.out
     1       2       3       4 
     5       6 
mweeks@air:C_ch5$ vi expr2.c 
mweeks@air:C_ch5$ cat expr2.c 
// expr1 : expr2 expr3
// Conditional operators
// "?" followed by ":"
//
// expr1? expr2:expr3;   // this means
// if expr1 is true then
//    expr2 
// else 
//   expr3

#include <stdio.h>

#define n 6

int main() {
  int a[n] = {101, 102, 103, 104, 105, 106};
  int i;

  for (i=0; i<n; i++) {
    printf("%6d %c",
      a[i], (i%4==3||i==(n-1))?'\n':' ');
  }
  return 0;
}
mweeks@air:C_ch5$ gcc expr2.c
mweeks@air:C_ch5$ ./a.out
   101     102     103     104 
   105     106 
mweeks@air:C_ch5$ ls
a.out		bitcount.c	expr.c		expr2.c
mweeks@air:C_ch5$ cd ..
mweeks@air:programs$ find . | grep modul
./C_ch8/modulus.c
mweeks@air:programs$ mv C_ch8/modulus.c C_ch5/
mweeks@air:programs$ cd C_ch5
mweeks@air:C_ch5$ cat modulus.c 
// Modulus operator ("%")
// modulus.c
    #include <stdio.h>
   
    int main () {
      for (int i=0; i<10; i++)
        printf("%d %% 5 is %d\n", i, (i%5));
   
      return 0;
    }

mweeks@air:C_ch5$ gcc modulus.c 
mweeks@air:C_ch5$ ./a.out
0 % 5 is 0
1 % 5 is 1
2 % 5 is 2
3 % 5 is 3
4 % 5 is 4
5 % 5 is 0
6 % 5 is 1
7 % 5 is 2
8 % 5 is 3
9 % 5 is 4
mweeks@air:C_ch5$ echo "operators and &, or |, exclusive or ^, left-shift <<, rigt-shift >>, 1s complement ~" 
operators and &, or |, exclusive or ^, left-shift <<, rigt-shift >>, 1s complement ~
mweeks@air:C_ch5$ echo " 0110   shift right  we get 0011"
 0110   shift right  we get 0011
mweeks@air:C_ch5$ echo " 0110   shift left  we get 1100"
 0110   shift left  we get 1100
mweeks@air:C_ch5$ exit
exit

Script done on Mon Sep 30 13:45:37 2024