Output indentation in C

Question

Basically I want to print something like this:

Process No.(Size)    Block No.(Size)
1(200)               3(300)
2(3)                 1(50)
3(1000)              4(1200)

Since the spacing is variable, how to do it by the width specifier in %d?

printf("%d(%d)%d(%d)",processNo,processSize,blockNo,blockSize)

Where to put the spacing value?

Answer 1

You can first print each 'field' of your table into a character string, then print each such field string using a left-justified, fixed-width format specifier. The latter is accomplished using the - flag and a width value in the %s format specifier (i.e., -n%s).

The following code displays what you require (I have used the fields to hold both the column titles and each row of data, but this is an 'optional extra').

#include <stdio.h>

int main(void)
{
    // Test data ...
    int procNo[3] = { 1, 2, 3 };
    int procSize[3] = { 200, 3, 1000};
    int blockNo[3] = { 3, 1, 4 };
    int blockSize[3] = { 300, 50, 1200 };

    char procField[32] = "Process No.(Size)";
    char blockField[32] = "Block No.(Size)";

    // Print rubric ...
    printf("%-22s%-22s\n", procField, blockField);

    // Print data rows ...
    for (int i = 0; i < 3; ++i) {
        // Write each field to string ...
        snprintf(procField, sizeof(procField), "%d(%d)", procNo[i], procSize[i]);
        snprintf(blockField, sizeof(blockField), "%d(%d)", blockNo[i], blockSize[i]);
        // ... then print fields as left-justified, fixed-length fields
        printf("%-22s%-22s\n", procField, blockField);
    }
    return 0;
}