Messy strings

[saneman]

I am trying to call gnuplot from C++. I have to make a system call
containing the command and path to a data file:

std::string path_to_data = "c:\\data.txt";
std::string gnuplot = "wgnuplot.exe";
std::string gnuplot_call = gnuplot + " " + path_to_data;
system(&gnuplot_call[0]);

But system wants a char*. Is there anyway to make the above more
simple/readable?

[Ian Collins]

saneman wrote:

I am trying to call gnuplot from C++. I have to make a system call
containing the command and path to a data file:

std::string path_to_data = "c:\\data.txt";
std::string gnuplot = "wgnuplot.exe";
std::string gnuplot_call = gnuplot + " " + path_to_data;
system(&gnuplot_call[0]);

But system wants a char*. Is there anyway to make the above more
simple/readable?

system() expects a const char*, so you should use gnuplot_call.c_str().

--
Ian Collins.

[blargg]

In article <6g************@mid.individual.net>, Ian Collins
<ia******@hotmail.comwrote:

saneman wrote:

I am trying to call gnuplot from C++. I have to make a system call
containing the command and path to a data file:

std::string path_to_data = "c:\\data.txt";
std::string gnuplot = "wgnuplot.exe";
std::string gnuplot_call = gnuplot + " " + path_to_data;
system(&gnuplot_call[0]);

But system wants a char*. Is there anyway to make the above more
simple/readable?

system() expects a const char*, so you should use gnuplot_call.c_str().

More importantly, it wants a nul-terminated string, which &gnuplot_call[0]
is not; only by bad luck would the undefined access past the end be a nul
character. c_str() is the only correct solution of the two above.