remove leading zeros

[huskers]

I have a short value and after performing some bit operations i use sprintf to print it to a character array. Is there any easy way to remove leading zeros.

 

[cdlvj]

sprintf(out,"%d",value);

%6d will puts leading zeroes out.

 

[huskers]

thanks for the reply. I allocate a string dynamically:

str=malloc(20);
str=""
for (....loop...)
{
/** here i do some calculations **/
sprintf(str,"%s%d",str,value);
}

the str1 contains 0000418.23. Is there an efficient way to remove leading zeros in str1 other than using %6d.

 

[cdlvj]

What is the value of the variable value.
and the string str?

The string shows a real number, and not an integer.

 

[itsgsd]

There are several ways to do this, here's one using a char pointer:

char *s;

s = str;
while (*s && *s == '0') s++; /* find the first non '0' element */
printf("%s\n",s); /* now use s instead of str */

Good luck.

 

[ArkM]

To huskers:
It seems the easiest way is: where is the source of zeroes? May be you can suppress its generation from the beginning?
If not, write a function to eat leading zeroes in ASCIIZ strings (the standard way in the spirit of good old C...

 

[mingis]

1.

> str=malloc(20);
> str="";

Second assignment forgets any memory allocations, after that you can use only one first byte of literal string "". sprint()'ing to such pointer will destroy any data. Should be

str[0]=0;

2.

> sprintf(str,"%s%d",str,value);

Using of same string as source and destination is dangerous, it would produce infinite loop if the format string would be for instance " %s%%d".

3.

> the str1 contains 0000418.23

such a result could be received only in case, when on entering to sprintf() str would contain "0000418." - source of zeroes is somewhere earlier.

4. Format specifier %6d has nothing to do with leading zeroes - its purpose is to add spaces in front of the number.

 

[ArkM]

I suspect that there is %07d specification or what else in sprintf format...

 

[SkiLift]

sprintf should not put leading zeros in the string.

itoa() is another possibilty.

 

[itsgsd]

sprintf(str,"%07d",3); results in "0000003"
sprintf(str,"%7d",3); results in " 3"
sprintf(str,"%d",3); results in "3"

But Huskers isn't using a width format specifier in his sprintf statement. It looks like He's starting with an empty string:
""
then basically concatenating the next value using sprintf:

1st loop: "0"
2nd loop: "00"
3rd loop: "000"
4th loop: "0000"
5th loop: "00004"
.
.
.
finally: "0000418.23"

(I'm still not sure where the decimal is coming from, but that's irrelevant)

The result is a numeric string with leading 0's that need to be stripped off.

Consider Eliminating the source of the leading 0's as ArkM suggested or something like I suggested earlier. There are, of course other ways to do the same thing.

Also, mingis pointed out some problems with the code.

Good luck.