How do I concatenate three strings?

[Mr. Ken]

In my function, my main calls a function to save the data. In script-based
languages like
matlab, I can use multiple in strcat. However, in C++ it's not working since
first argument
of strcat must be the destination.

How can I get arround?





main{

.....
fname = "_0100_0211"; // from somewhere
save_messages(......, char fname);
.....


return (0);
}


function save_messages(......, char fname[100])
{
fname = strcat("MSG_INP_", fname, ".DAT");
fp = fopen(fname, "w");
blah blah
fclose(fp);

fname = strcat("MOD_OUT_", fname, ".DAT");
fp = fopen(fname, "w");
blah blah
fclose(fp);
.....
....

}

 

[Ian Collins]

In my function, my main calls a function to save the data. In script-based
languages like
matlab, I can use multiple in strcat. However, in C++ it's not working since
first argument
of strcat must be the destination.

How can I get arround?

Use std::string rather that C style "strings".

You can concatenate strings with the + operator, or by using a stringstream.

 

[Allan M. Bruce]

In my function, my main calls a function to save the data. In script-based
languages like
matlab, I can use multiple in strcat. However, in C++ it's not working
since
first argument
of strcat must be the destination.

How can I get arround?





main{

....
fname = "_0100_0211"; // from somewhere
save_messages(......, char fname);
....


return (0);
}


function save_messages(......, char fname[100])
{
fname = strcat("MSG_INP_", fname, ".DAT");
fp = fopen(fname, "w");
blah blah
fclose(fp);

fname = strcat("MOD_OUT_", fname, ".DAT");
fp = fopen(fname, "w");
blah blah
fclose(fp);
....
...

}

If you insist in using C style strings, have a look at sprintf() - it should
help you achieve what you want.
Allan

 

[Allan M. Bruce]

Thank you, I am using sprintf now.
My primary style is generic C, which I feel is more portable, and my
program
inherits
from some old work which is in C.

If I use Dev-C++ 4.9, can I use both C and C++ statements in one file? In
this way, the
old statements continue to work but I can add new ones with simpler C++
statements.

#include <string.h>
#include <string>

Yes it is possible to use C syntax within C++ programs to a large extent.
The official header for C string operations is <cstring>

Allan

 

[Mr. Ken]

If you insist in using C style strings, have a look at sprintf() - it should
help you achieve what you want.
Allan

Thank you, I am using sprintf now.
My primary style is generic C, which I feel is more portable, and my program
inherits
from some old work which is in C.

If I use Dev-C++ 4.9, can I use both C and C++ statements in one file? In
this way, the
old statements continue to work but I can add new ones with simpler C++
statements.

#include <string.h>
#include <string>

 

[Rolf Magnus]

If I use Dev-C++ 4.9, can I use both C and C++ statements in one file? In
this way, the old statements continue to work but I can add new ones with
simpler C++ statements.

Well, there are some differences in C and C++, so you might need some tweaks
here and there, but C++ mostly supports C as a subset.