can you make an ifstream from a FILE* ?

[George]

Hi All,

In trying to learn streams I'd like to rewrite this from the popen man
page:

#include <stdio.h>
#include <stdlib.h>
main( )
{
char *cmd = "/usr/bin/ls *.c";
char buf[BUFSIZ];
FILE *ptr;

if ((ptr = popen(cmd, "r")) != NULL)
while (fgets(buf, BUFSIZ, ptr) != NULL)
(void) printf("%s", buf);
(void) pclose(ptr);
return 0;
}


I was going to try to use istream_iterator and std::copy. Is it
possible to get the FILE* into an ifstream object?

Thanks much for my stupid question. Sincerely, G

 

[BobR]

George wrote in message

Hi All,

In trying to learn streams I'd like to rewrite this from the popen man
page:

<an uneducated suggestion>
Look in the iostream docs:

"Reading/writing from/to a pipe"

The procbuf class is a GNU extension. It is derived from streambuf. A procbuf
can be closed (in which case it does nothing), or open (in which case it
allows communicating through a pipe with some other program).

Constructor: procbuf:rocbuf (const char *command, int mode)
Calls `procbuf:pen (command, mode)'.

 

[Neil Cerutti]

Hi All,

In trying to learn streams I'd like to rewrite this from the popen man
page:

#include <stdio.h>
#include <stdlib.h>
main( )
{
char *cmd = "/usr/bin/ls *.c";
char buf[BUFSIZ];
FILE *ptr;

if ((ptr = popen(cmd, "r")) != NULL)
while (fgets(buf, BUFSIZ, ptr) != NULL)
(void) printf("%s", buf);
(void) pclose(ptr);
return 0;
}


I was going to try to use istream_iterator and std::copy. Is
it possible to get the FILE* into an ifstream object?

A quick perusal of my docs and the draft standard suggests it is
not possible with a standard function.

 

[George]

Awesome, thanks much all for the tips