Programming

i am having a string like

" X1 " ---> string lenght is 30

I have stored this to a chararry . ref[30]

so here ref = " X1 "

now i trim the left space by my function . Si the string now becomes

"X1 " ---> string lenght is 15

I want this string as 30 character array , when i tried to print after trining the space it is becoming 15 in length

After triming on the 30 character array , i need to add the balnk space in the end .

in short after i do a trim the string should be as

"X1 " --- correct
"X1 " --> incorrect now after triming i am getting like i am not able to achieve the above

can you please help me to do this achieved

Thanks,
Arun

These are standard little tools C programmers use:

Code:

#include <string.h>
#include <stdlib.h>
#include <ctype.h>

char *ltrim(char *dest)
{
	if(*dest)
	{
		char *working=calloc(1,strlen(dest)+1);
		char *p=dest;
		while(isspace(*p)) p++;
		strcpy(working,p);
		strcpy(dest, working);
		free(working);
	}
	return dest;
}

char *rpad(char *dest, size_t len, int padchar)
{
    if(strlen(dest) < len)
    {
		char *working=calloc(1, len+1);
	    memset(working, padchar, len);
	    memcpy(working, dest, strlen(dest));
	    strcpy(dest, working);
		free(working);
	}
	return dest;
}

int main()
{
	char test[64]={0x0};
	strcpy(test, " X");
	printf("before :%s: ", test);
	ltrim(test);
	printf("After ltrim :%s: ", test);
	rpad(test, 32, ' ');
	printf("after rpad  :%s:\n", test);
	return 0;
}

Can you show the source of the trim function

Here's another way to do it - I barely tested it, but it looks like it works.

namespace cpp_stl_method
{
using namespace std;

#define whitespaces ((char*)" \f\v\r\n\t")
inline void ltrim(string& s,char* ws=whitespaces)
{
int fs=s.find_first_not_of(ws);
if ((fs!=string::npos) && (fs>0)) s.erase(0,fs);
}

inline void rpad(string&s, int n, char ch)
{
int l=n-s.size();
if (l>0) s.append(l,ch);
}

int main()
{
string test; test=" X";
cout<<"before :"<<test<<": ";
ltrim(test);
cout<<"After ltrim :"<<test<<": ";
rpad(test, 32, ' ');
cout<<"after rpad :"<<test<<":"<<endl;
return 0;
}
} // cpp_stl_method


int main()
{
// Cmethod::main(); // you can try the C method here and compare the results
cpp_stl_method::main();
}