beginner question in C ?

[tolgao]

Hello,

I am learning C through the book
"The C Programming Language", 2nd edition, Kernighan and Ritchie


I am on exercise, 1-10. I did not understand the below answer in this exercise.

Question:
Write a program to copy its input to its output, replacing each tab by \t , each backspace by \b , and each backslash by \\ . This makes tabs and backspaces visible in an unambiguous way.

Answer:

int main()
{
int c, d;

while ( (c=getchar()) != EOF) {
d = 0;
if (c == '\\') {
putchar('\\');
putchar('\\');
d = 1;
}
if (c == '\t') {
putchar('\\');
putchar('t');
d = 1;
}
if (c == '\b') {
putchar('\\');
putchar('b');
d = 1;
}
if (d == 0)
putchar(c);
}
return 0;
}
Why do you use two putchar statements:

for example :

putchar('\\');
putchar('t');
why do you need putchar( ' \\ ') ? What does it do ?

also what is the purpose of variable d ?

Also, Is there another way to write this code ?


Thanks,
Tolga

[Koorakula Bala Manikanta]

hiiiiiiiii dude,

we use // in the above program,because in output we can see the tab=\t symbol in the form tab and space=\s....

see the out put :


mani kanta bala

mani\skanta\tbala

(instead of space and tab ,\s \t)

you try this

printf(" \Hello World \\ backslash" );

the output : Hello World \ backslash

[guptamahesh]

they are literaaly ambiguious you shud refer "let us c" book by yashwant karnetkar....if u dont have i have an ebokk...let me know

[poojadreams]

yashwant karnetkar book is very useful for basics. It is clearly explained. Even newbie can understand it. You will get basics very clear.

[kevinm]

I used to refer yashwant karnetkar. Nice book

[venkatjaya]

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