c functon to set the gateway

[madhumathikv]

I have a c function to set the gateway :-

if ((ofp = fopen(IF_CONF ".out", "w")) == NULL) 
{
        printf("Unable to open interface configuration file: %s.\n", strerror(errno));
        fclose(fp);
        return -1;
 } 
 

-->IF_CONF contains the path of the file to where the gateway ip should be written.


--->It's giving the output as Unable to open interface configuration file:Permission Denied.
-->I have set all the permission for the file IF_CONF..

-->how can i come out of this.

-->please any one help.

[sicarie]

I've never tried it that way, but I'm pretty sure your issue lies with IF_CONF ".out" and how there is nothing to join those two together. (Here I am guessing IF_CONF is a string or char*)

Have a look at this thread - I think the OP there is doing a similar thing that you want to be doing there (condensing that into a single string variable).

[Banfa]

I'm pretty sure your issue lies with IF_CONF ".out" and how there is nothing to join those two together. (Here I am guessing IF_CONF is a string or char*)

No that is quite alright assuming that IF_CONF is defined something like

#define IF_CONF "c:\\SomeDirectory\\SomeFile"
 

The C (and C++) compiler automatically contatinates strings that appear in the code with nothing but whitespace between them.

This is a useful feature as it allows you to easily split long strings across several code lines.

Try this

#include "stdio.h"
 
int main(int argc, char **argv)
{
    puts("He" "ll" "o " 
         "Wo" "rl" "d!" );
 
    return 0;
}
 

[sicarie]

No that is quite alright assuming that IF_CONF is defined something like

#define IF_CONF "c:\\SomeDirectory\\SomeFile"
 

The C (and C++) compiler automatically contatinates strings that appear in the code with nothing but whitespace between them.

This is a useful feature as it allows you to easily split long strings across several code lines.

Try this

#include "stdio.h"
 
int main(int argc, char **argv)
{
    puts("He" "ll" "o " 
         "Wo" "rl" "d!" );
 
    return 0;
}
 

Wow, that's interesting. Cool, though, you could have some fun with that. Thanks, Banfa.

So do you think the OP's issue is with the file permissions on what they are creating, or the directory it is being created in?

[Banfa]

So do you think the OP's issue is with the file permissions on what they are creating, or the directory it is being created in?

Possibly or may be just an error in coding the file name, for instance \ instead of \\ or plain getting it wrong.

[madhumathikv]

Possibly or may be just an error in coding the file name, for instance \ instead of \\ or plain getting it wrong.

Ya as Banfa told IF_CONF has been defined like
#define IF_CONF "/etc/sysconfig/network-scripts/ifcfg-eth0"


-->I am using linux machine.
-->I have given all the permission for that file.

So what do you think the solution is.

[Banfa]

I trust you have tried to create/open /etc/sysconfig/network-scripts/ifcfg-eth0.out with a normal test editor to make sure you can.

[madhumathikv]

No that is quite alright assuming that IF_CONF is defined something like

#define IF_CONF "c:\\SomeDirectory\\SomeFile"
 

The C (and C++) compiler automatically contatinates strings that appear in the code with nothing but whitespace between them.

This is a useful feature as it allows you to easily split long strings across several code lines.

Try this

#include "stdio.h"
 
int main(int argc, char **argv)
{
    puts("He" "ll" "o " 
         "Wo" "rl" "d!" );
 
    return 0;
}
 

ya you are correct.. it is like that oonly.