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can we send arguments to system() call

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# 1  
Old 08-14-2006
can we send arguments to system() call
Hi friends

my C code is

int main()
{
system("cp <source> <destination>");
}

my question is
how to set variables for <source> and <destination>
how can we pass it to system() call.

can you suggest me
thankyou
kingskar
# 2  
Old 08-14-2006
In such situations it's always better to do a combination of fork and one of the exec family member.

if(fork()==0){
//do nothing
}
else{

exec....( what ever suits you)

}

You can also check the exec man page to see the all members of exec family!!

regards
Apoorva kumar
# 3  
Old 08-14-2006
Thankyou apoorva
Thankyou for your valuable suggestion

Cheers
Shekar
# 4  
Old 08-14-2006
vfork and exec - that is what is done in system function call..

and to answer your question, something like this would do..
Code:
/* source file in char source[512] and dest file in char dest[512] */
char str[512];
memset(str, '\0', sizeof(512));
sprintf(str, "/usr/bin/cp %s %s", source, dest);
ret=system(str);

# 5  
Old 08-17-2006
Quote:
Originally Posted by matrixmadhan
vfork and exec - that is what is done in system function call..

and to answer your question, something like this would do..
Code:
/* source file in char source[512] and dest file in char dest[512] */
char str[512];
memset(str, '\0', sizeof(512));
sprintf(str, "/usr/bin/cp %s %s", source, dest);
ret=system(str);


Yes
your code is exactly fits for my requirement.
Thankyou
Cheers
kingskar
# 6  
Old 08-17-2006
if you are using glibc it may be better to use:
#define _GNU_SOURCE
#include <stdio.h>

char *buf;
asprintf(&buf,"cp %s/%s",src,dst); /* do not forget error check */
system(buf);
free(buf);

the advantage is that you have no limits for pathlenght.
you can also emulate asprintf with 2 calls to snprintf()
# 7  
Old 08-17-2006
what is the need to use free here ?
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