The ascii table program

$ls
ascii-table.c   avg-with-garbage.txt  env-var-set.c     functions_ver2.c  output.c
ascii-table.md  case-changer.c        exist.sh          mph-to-kph.c
avg.txt         env-var.c             functions_ver1.c  mph-to-kph_v2.c
$cat ascii-table.c 
#include <stdio.h>

int main(void)
{
    char c;
    for (c = 65; c<=90; c++)
    {
        printf("%c = %d    ", c, c); /* upper case */
        printf("%c = %d\n", c+32, c+32); /* lower case */
    }
    return 0;
}
$gcc ascii-table.c -o ascii-table
$./ascii-table 
A = 65    a = 97
B = 66    b = 98
C = 67    c = 99
D = 68    d = 100
E = 69    e = 101
F = 70    f = 102
G = 71    g = 103
H = 72    h = 104
I = 73    i = 105
J = 74    j = 106
K = 75    k = 107
L = 76    l = 108
M = 77    m = 109
N = 78    n = 110
O = 79    o = 111
P = 80    p = 112
Q = 81    q = 113
R = 82    r = 114
S = 83    s = 115
T = 84    t = 116
U = 85    u = 117
V = 86    v = 118
W = 87    w = 119
X = 88    x = 120
Y = 89    y = 121
Z = 90    z = 122
$