How to execute external program and process its output?

Hello! I am trying to execute external command from D program, and then process its output. spawnvp() doesn't seem to be enough as it does not return output, but just status as int. How to achieve it in D (I don't know method also in C(++), so even this will help <g>)? --- Regards Marcin Kuszczak (Aarti_pl)

Marcin Kuszczak wrote: > Hello! > > I am trying to execute external command from D program, and then process its > output. spawnvp() doesn't seem to be enough as it does not return output, > but just status as int. > > How to achieve it in D (I don't know method also in C(++), so even this will > help <g>)? > > --- > Regards > Marcin Kuszczak > (Aarti_pl) Marcin, I don't know the "correct" way to do this, but perhaps I can offer a short-term hack to get you by? char[] commandline = "echo 'hello world' > output.txt"; std.process.system(commandline); writefln("result: %s",std.file.read("output.txt")); Sure its not pretty, but it does work.

Pragma wrote: > char[] commandline = "echo 'hello world' > output.txt"; > std.process.system(commandline); > writefln("result: %s",std.file.read("output.txt")); I had to modify a little bit program, but then it works - thanks a lot! -- void main() { char[] commandline = "svn info >output.txt 2>&1"; std.process.system(commandline); char[] result = cast(char[])(std.file.read("output.txt")); writefln("result: %s", result); } -- In the meantime I found also that there should be functions on C API -- #include <stdio.h> FILE *popen( const char *command, const char *type); int pclose( FILE *stream); -- but as I see it is not wrapped by D. I don't have any idea how to do it. If anyone can give some more info it would be great. BTW if D wants to be also language for scripting, it should have such a possibility in standard library. -- Regards Marcin Kuszczak (Aarti_pl)

Marcin Kuszczak wrote: > Pragma wrote: > >> char[] commandline = "echo 'hello world' > output.txt"; >> std.process.system(commandline); >> writefln("result: %s",std.file.read("output.txt")); > > I had to modify a little bit program, but then it works - thanks a lot! > > -- > void main() { > char[] commandline = "svn info >output.txt 2>&1"; > std.process.system(commandline); > char[] result = cast(char[])(std.file.read("output.txt")); writefln("result: %s", result); > } > -- > > In the meantime I found also that there should be functions on C API > > -- > #include <stdio.h> > FILE *popen( const char *command, const char *type); > int pclose( FILE *stream); > -- > > but as I see it is not wrapped by D. I don't have any idea how to do it. If > anyone can give some more info it would be great. extern (C) { typedef void FILE; FILE* popen(char* cmd, char* type); int pclose(FILE* stream); } should work

Marcin Kuszczak wrote: > Hello! > > I am trying to execute external command from D program, and then process its > output. spawnvp() doesn't seem to be enough as it does not return output, > but just status as int. > > How to achieve it in D (I don't know method also in C(++), so even this will > help <g>)? > > --- > Regards > Marcin Kuszczak > (Aarti_pl) IIRC somewhere back a few months ago, someone made a stream object that did just what you want. You could even write to the program's standard input by outputting to the stream.