how to split a char array into two smaller ones, and end well..

Projects Programming
1

char text[21] //contains a 0x00 terminated string between 5..20 characters
char textA[11] //is expected to contain the first 10 chars
char textB[11] //is expected to contain the second 10 chars

// so if text is "0123456789ABCD" , then textA should be "0123456789"
//text B should be "ABCD " (10 characters)

strncpy (textA, text, 11); //should fill the first string , but if text is shorter than 10, it won't be padded with extra space characters.

how to fill the second one , (from offset 10 to 20) , I don't know

All I can think of is a for loop that copies one character at a time. (then it would be easy to overwrite the remaining characters with space or 0x0 too)

2

strcpy(textB, text+10, 11);

3

All I can think of is a for loop that copies one character at a time. (then it would be easy to overwrite the remaining characters with space or 0x0 too)

And the problem with that is?

4

Use the printf family

char text[21]  //contains a 0x00 terminated string between 5..20 characters
char textA[11]  //is expected to contain the first 10 chars
char textB[11]  //is expected to contain the second 10 chars

char tmp[11];

strcpy(text, "0123456789ABCDEF");

// fill tmp with 0x00
memset(tmp, 0, sizeof(tmp);

// copy first 10 characters (or less) to tmp
strncpy(tmp, text, 10);
// pad
snprintf(textA, sizeof(textA), "%-10s", tmp);

// fill tmp with 0x00
memset(tmp, 0, sizeof(tmp);

// copy second 10 characters (or less) to tmp
strncpy(tmp, &text[10], 10);
// pad
snprintf(textB, sizeof(textB), "%-10s", tmp);

Looping might be cheaper from a memory usage perspective.

5

You could make it a union and save the copying entirely.

6

Thank you all. - I'll try all methods for efficiency.