solution to the problem

[vapanchamukhi]

i want to replace the tab with \t , space with \s and back slash with
\\, from input to output.
i wrote the program like below. so tell me some one why it is wrong...

main()
{
      int c;
      
      while((c = getchar()) != EOF) {
               if(c == ' ') 
                     printf("\\s");
               else if(c == '\t')
                      printf("\\t");
                else if(c == '\')
                      printf("\\\\");
               else
                      putchar(c);
        }
}

[matsp]

You want to replace

space with \s

and your code does:

               if(c == ' ') 
                     printf("\\b");

Does that seem right?

so tell me some one why it is wrong

It would of course help if you on your side explained "How it is different from what you expect", since we can only guess on what is not working....

--
Mats

[vapanchamukhi]

no im sorry... but thats not what im asking. its giving errors that ' missing, } missing. so i want to know whether what i have written is write or wrong. if it is wrong then where i have done mistake....

[matsp]

Have a look at this line, then:

else if(c == '\')

What does it actually produce?

--
Mats

[vapanchamukhi]

my intention of writing that line is if i give \ as input then that character is compared with \... isn't???

[Sebastiani]

Except that the backslash is the escape character, so you are actually escaping a single quote, which is obviously not what you want...

[QuantumPete]

my intention of writing that line is if i give \ as input then that character is compared with \... isn't???

mmm, yes. But the compiler will want to interpret things for you. It's uselessly clever like that It thinks you're trying to escape the second ' and hence you don't have a closing apostrophe. I think all you need is to compare c with '\\'.

QuantumPete

[vapanchamukhi]

ya now 0 errors.. i compiled successfully. but now it is not giving any thing as output..

[matsp]

ya now 0 errors.. i compiled successfully. but now it is not giving any thing as output..

That is very strange, as I would expect it to at least output back what you have input after you hit enter. In fact, it works just like I expect when I run it here.

--
Mats

[QuantumPete]

post your code again, maybe another error crept in somewhere.

QuantumPete

[vapanchamukhi]

ya it works fine... i had done mistake while writing that program in vim editor... instead of assigning the value of getchar() i had used ==... thats because of that it was not showing any thing.... now it works fine...

[QuantumPete]

That means you're not compiling with any of the warning flags. You should always include -Wall in your gcc commandline. That should have flagged up this problem as a warning.

QuantumPete

[vapanchamukhi]

ya actually i used to compile using cc not gcc. is there any such option in cc..

[matsp]

ya actually i used to compile using cc not gcc. is there any such option in cc..

What OS are you using? If it's Linux, then cc == gcc. Otherwise, we'd need to know what compiler it is...

--
Mats

[vapanchamukhi]

ok thanks... i dint know that... i work in fedora linux.