string trim

[tanarnelinistit]

If I have a string definfed as this: char sir[17] how can i remove any new line or carriage return from the end or the begining of it?

[_AnsHUMAN_]

tanarnelinistit wrote

remove any new line or carriage return

void check(char p[])
{
	for(int i=0;i <   strlen(p)-1;i++)
	{
		if(p[i]=='\n')
			//Don't copy to another location
                else
                        // Copy char to another one
// Similarly check for /r
	}
} 

Somethings seem HARD to do, until we know how to do them. ;-)_AnShUmAn_

[James R Twine]

Go the end of the string, start backing up character-by-character while whitespace (or whatever you want to trim) is found.  When you find the first non-matching character, place a NUL into that location to terminate the string at that point.    You do not have to do something crazy like copying the string or moving it into and out of a string object.    Peace!

-=- James

---

If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Avoid driving a vehicle taller than you and remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
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[David Crow]

tanarnelinistit wrote:

how can i remove any new line or carriage return from the...begining of it?

Something like the following comes to mind:

void TrimLeft( char *str, const char ch )
{
char *pStr = str;

// locate first non-matching character
while (ch == \*pStr)
    pStr++;

strcpy(str, pStr);

}

Fine tune it to fit your needs.

---

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

[Zac Howland]

Method using CString:

char buffer[17] = {0};
InitializeBuffer(buffer);	// put some value into it
CString strBuffer(buffer);
strBuffer.TrimLeft();
strBuffer.TrimRight();
memset(buffer, 0, 17);
strncpy(buffer, strBuffer, 16);

Method using std::string:

char buffer[17] = {0};
InitializeBuffer(buffer);	// put some value into it
std::string sBuffer(buffer);
int start_pos = sBuffer.find_first_not_of("\t\n\r ");
int end_pos = sBuffer.find_last_not_of("\t\n\r ");
if (start_pos == npos)
{
	start_pos = 0;
}
if (end_pos = npos)
{
	end_pos = strlen(buffer) - 1;
}
std::string sTemp = sBuffer.substr(start_pos, end_pos - start_pos + 1);
memset(buffer, 0, 17);
strncpy(buffer, sTemp.c_str(), 16);

Method using char:

int FindFirstNotOf(const char* chars, size_t chars_size, const char* str, size_t str_size)
{
	int ret = -1;
	for (int i = 0; i < str_size; ++i)
	{
		bool bFound = false;
		for (int j = 0; j < chars_size; ++j)
		{
			if (str[i] == chars[j])
			{
				bFound = true;
				break;
			}
		}

		if (bFound == false)
		{
			ret = i;
			break;
		}
	}
	
	return ret;
}

int FindLastNotOf(const char* chars, size_t chars_size, const char* str, size_t str_size)
{
	int ret = -1;
	for (int i = str_size - 1; i >= 0; --i)
	{
		bool bFound = false;
		for (int j = 0; j < chars_size; ++j)
		{
			if (str[i] == chars[j])
			{
				bFound = true;
				break;
			}
		}

		if (bFound == false)
		{
			ret = i;
			break;
		}
	}
	
	return ret;
}

char buffer[17] = {0};
InitializeBuffer(buffer);	// put some value in there
char chars[5] = "\t\r\n ";
int start_pos = FindFirstNotOf(chars, 5, buffer, 17);
int end_pos = FindLastNotOf(chars, 5, buffer, 17);

if (start_pos == -1)
{
	start_pos = 0;
}

if (end_pos == -1)
{
	end_pos = strlen(buffer) - 1;
}

char newBuffer[17] = {0};
strncpy(newBuffer, &buffer[start_pos], end_pos - start_pos);
memset(buffer, 0, 17);
strncpy(buffer, newBuffer, 16);

If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week Zac

[James R Twine]

OK - perhaps a simple example of trimming a string in-place, because you did not mention the word "copy" in your post (this code comes slightly modified from my TStaticString class):

void TrimRight( LPTSTR cpString,
LPCTSTR cpTrimWhat = _T( " " ) ) // Trim Trailing Characters From String
{
size_t stStrLen = ::_tcslen( cpString ); // Get String Length

if( !stStrLen )                                     // If No String Length
{
    return;                                         // Stop Here
}
LPTSTR  cpCursor = ( cpString + ( stStrLen - 1 ) ); // Start At End Of String (Not The NUL Terminator)
size\_t  stCount = 0;

while( ( stCount < stStrLen) &&                     // While String Characters Available
        ( ::\_tcschr( cpTrimWhat, \*cpCursor ) ) )    // Look For Target To Remove
{
    ++stCount;                                      // Increment Count While Found
    --cpCursor;                                     // Decrement Cursor Location
}
if( stCount )                                       // If Trimming Characters Found
{
    ++cpCursor;                                     // Advance Cursor Back To Last Trailing Character
    \*cpCursor = \_T( '\\0' );                         // Terminate The String Right There
}
return;                                             // Done!

}

See how that works for you.  Specify the characters to   Example of use:

TCHAR   caTest\[ 32 \];

strcpy( caTest, \_T( "abc\\t   " ) );
TrimRight( caTest );
strcpy( caTest, \_T( "abc\\t   " ) );
TrimRight( caTest, "\\t " );

The first call will trim up to the tab character, the second will also trim the tab character.    Peace!

-=- James

---

If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Avoid driving a vehicle taller than you and remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
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[Blake Miller]

What about beginning of string?

Any sufficiently gross incompetence is nearly indistinguishable from malice.

[James R Twine]

Just reverse the algorithm, being sure not to walk past the end of the string.    Peace!

-=- James

---

If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Avoid driving a vehicle taller than you and remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
DeleteFXPFiles & CheckFavorites (Please rate this post!)