need help with search and replace function

[liftthis]

I am trying to remove blank spaces and replace them to '_' . This program works when you have a defined string, but I am using a string the user propulates from edit txt box or console cin input. It will not display the whole filename. I suspect I am mixing C and C++.

Please help.

Here is the code:

#include <iostream>
#include <string>
using namespace std;

int main()
{

//char out_file_name[19];
string out_file_name;

cout << " Enter output file name with no extention followed by a return \n ";
cout << '\n';
cout << " (For example training ";
cin >> out_file_name;

// string s = "All this will be replaced by this";
string s = out_file_name;
string toFind = " ";
string replaceWith = "_";

// before find and replace
cout << s << endl;

// find and replace operation
int pos;
while ((pos = s.find(toFind)) != string::npos)
s.replace(pos,toFind.size(),replaceWith);

// after find and replace
cout << s << endl;

return 0;
}

[Philip Nicoletti]

1) you are reading in the filename using operator >> , which stops
reading when it encounters a whitespace. I assume that you want
to read everything ... use getline

getline(cin,out_file_name);

Note: if you have to hit enter twice for getline to work, you are using
an old (bugged) version ... you can get the updated code at :

http://www.dinkumware.com/vc_fixes.html

see fix to <istream> and <string>

2) I doubt that you really want to replace space with '_' , but
if you do ... use std::replace ...

#include <algorithm>

replace(out_file_name.begin(),out_file_name.end(),' ','_');

[liftthis]

I looked at some examples and it is still confusing.

[Philip Nicoletti]

?? Some examples of what ??

[liftthis]

I want to use user input and It won't work. Need help.

The first examples will works:

/ replacing in a string
#include <iostream>
#include <string>
using namespace std;

int main ()
{

string s = "this is a test";

int x = s.find(" ");
while (x < string::npos)
{
s.replace(x,1,"_");
x = s.find(" ", x +1);
}

cout << s << endl;

return 0;
}


This second example does not work. It does not get the whole string. It only display to the white space.

/ replacing in a string
#include <iostream>
#include <string>
using namespace std;

int main ()
{


char s1[255];



cout << " Enter output file name with no extention followed by a return \n ";
cout << '\n';
cout << " (For example training ";
cin >> s1;

string s = s1;


int x = s.find(" ");
while (x < string::npos)
{
s.replace(x,1,"_");
x = s.find(" ", x +1);
}

cout << s << endl;

return 0;

[liftthis]

I know that strings are delimited by whitespace characters, which is causing my problem. does anybody know how I can prevent this.

[Philip Nicoletti]

see my very first post ... use getline() not operator >>

[liftthis]

I got the prototype working using the getline, but I tried to intergrate to the logic below.

Now I get the following errors.
Can some help with these errors.

error C2872: 'ofstream' : ambiguous symbol
error C2872: 'cout' : ambiguous symbol
error C2872: 'cin' : ambiguous symbol
error C2664: 'strcat' : cannot convert parameter 1 from 'class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >' to 'char *'
No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called




-----------------------------------------------------------------------------
#include <stdio.h>
#include <fstream.h>
#include <iostream.h>
#include <iomanip.h>
#include <stdlib.h>
#include <string>
#include <windows.h>
#include <time.h> //added for time and date
#include <iostream>

using namespace std;


char img_string[] = {'<','D','I','V',' ','a','l','i','g','n','=','"',
'l','e','f','t','"','>','<','I','M','G',' ','s','r','c',
'=','"','C','a','p','t','u','r','e','.','j','p','g',
'"','>','<','/','D','I','V','>','\0'};


static FILE *fp = NULL;

void main()
{


ofstream out_stream;


time_t rawtime; // added for time

time ( &rawtime ); //added for time


char * datetime = ctime (&rawtime);


//char out_file_name[256];

char filedir [200];

char s1[256];




cout << " Enter output file name with no extention followed by a return \n ";
cout << '\n';
cout << " (For example training ";
//cin >> out_file_name;

cin.getline (s1,256);

string out_file_name = s1;


int x = out_file_name.find(" ");
while (x < string::npos)
{
out_file_name.replace(x,1,"_");
x = out_file_name.find(" ", x +1);
}



strcat(out_file_name,".html");

strcpy (filedir, "C:\\training_output\\");
strcat (filedir, out_file_name);

out_stream.open (filedir);
if (out_stream.fail( ))
{
cout << "Output file opening failed.\n";
exit(1);
}

out_stream << "<HTML>" << '\n';
out_stream << "<TITLE>test" << '\n';
out_stream << "</TITLE>" << '\n';
out_stream << "<BODY>" << '\n';

[Philip Nicoletti]

YOu are including both <iostream> and <iostream.h> ...

you should not be using the .h version of the C++ headers. They
are non-standard and will not even compile using newer
compilers. Your headers should be :

#include <stdio.h>    // ok but better would be <cstdio>
#include <fstream>
#include <iomanip>
#include <stdlib.h>   // ok but better would be <cstdlib>
#include <string>
#include <windows.h>
#include <time.h>     // ok but better would be <ctime>
#include <iostream>
#include <algorithm>  // for std::replace

Also, you are mixing std::string and c-stycle char arrays .. which will
cause problems when using strcat() etc. I would recommend using
std::string only , unless it is absolutely necessary to use c-style
char arrays.

A simplified version of the relevant code:

    string out_file_name;
    getline (cin,out_file_name);

    replace(out_file_name.begin(),out_file_name.end(),' ','_');  // why ???

    out_file_name += ".html";

    string filedir = "C:\\training_output\\" + out_file_name;

    out_stream.open (filedir.c_str());

[liftthis]

another other problem: I used to use the following commented code.



// char systemcall[ ] = "START C:/training_output/";

// char text[255];


// strcat(systemcall,out_file_name);
// strcpy(text,systemcall);


// system(text);


Now I am Trying to use:

string systemcall = "START" + filedir;

system(systemcall);

[Philip Nicoletti]

system() takes a const char * variable, not a std::string variable ...
you can use the c_str() member function to get a const char * ...

system(systemcall.c_str());

(and make sure you put a space after START)

[dhawan]

hi,
can consider other way by "strtok" function.

regards
dhawan