I have a program which I wish to modify. It used to be run from the command line, but now I wish to change this so it can be used as a function.
The program has complex argument processing so I want to pass my paramters to as if it were being called by the OS as a program.
I have tried to... (2 Replies)
I searched on the forums. No advises.
I am using a previous source code. I changed the main function main(int argc, char **argv) in a function misc(int argc, char **argv). How do you use the argc and argv parameters? This is how I am calling the function :
char param;
strcat(param,"wgrib ");... (4 Replies)
I have a script that asks a bunch of questions using the following method for input:
print "Name:";
while(<>){
chomp;
$name=$_;
}
So for example, if the questions asked for name, age, & color (in that order)... I want to be able to easily convert $ARGV into the input expected by... (2 Replies)
Hi C experts,
I have the following code for adding command line option for a program
int main (argc, argv)
int argc;
char *argv;
{
char *mem_type; //memory type
char *name; //name of the memory
int addr; //address bits
int data; ... (5 Replies)
this is in one of my scripts...
if ($#argv == 0) then
echo 'blah bla'
exit 0
endif
I want it to be something like this...
if ($#argv == 0 OR $argv >=3)
echo 'blah bla'
exit 0
endif
so when the arguments are none, or greater than three I want this "if then" to take over. how? I... (5 Replies)
Hello all,
Had a quick question:
In a typical csh script should inputting via stdin (i.e. set i = $< ) increase the value of $#argv ?
echo enter an value:
set val= "$<"
if($#argv == 0) then
echo No args
else
echo The arg is $argv
so if a value is inputted #argv... (1 Reply)
when i run my program, i have a parameter, that i want to set the value to another string
i am using
int main(int argc, char **argv) {
char my_str=argv;
printf("%s",my_str);
return 0;
}
and i get
Segmentation fault
ran using
./my_prog /usr/share/dict/words hello1
... (2 Replies)
I'm working on my own pow function and I need to make a copy of *argv but
I think that I am having trouble with the size of *argv and the size of any array that I
make. The code below isn't working for me. and I want to accept any number no
matter the size with pow -f 2 2. I was working out... (16 Replies)
All of my machines (various open source derivatives on x86 and amd64) store argv above the stack (at a higher memory address). I am curious to learn if any systems store argv below the stack (at a lower memory address).
I am particularly interested in proprietary Unices, such as Solaris, HP-UX,... (9 Replies)
Discussion started by: alister
9 Replies
LEARN ABOUT OSX
net::netent
Net::netent(3pm) Perl Programmers Reference Guide Net::netent(3pm)NAME
Net::netent - by-name interface to Perl's built-in getnet*() functions
SYNOPSIS
use Net::netent qw(:FIELDS);
getnetbyname("loopback") or die "bad net";
printf "%s is %08X
", $n_name, $n_net;
use Net::netent;
$n = getnetbyname("loopback") or die "bad net";
{ # there's gotta be a better way, eh?
@bytes = unpack("C4", pack("N", $n->net));
shift @bytes while @bytes && $bytes[0] == 0;
}
printf "%s is %08X [%d.%d.%d.%d]
", $n->name, $n->net, @bytes;
DESCRIPTION
This module's default exports override the core getnetbyname() and getnetbyaddr() functions, replacing them with versions that return
"Net::netent" objects. This object has methods that return the similarly named structure field name from the C's netent structure from
netdb.h; namely name, aliases, addrtype, and net. The aliases method returns an array reference, the rest scalars.
You may also import all the structure fields directly into your namespace as regular variables using the :FIELDS import tag. (Note that
this still overrides your core functions.) Access these fields as variables named with a preceding "n_". Thus, "$net_obj->name()"
corresponds to $n_name if you import the fields. Array references are available as regular array variables, so for example "@{
$net_obj->aliases() }" would be simply @n_aliases.
The getnet() function is a simple front-end that forwards a numeric argument to getnetbyaddr(), and the rest to getnetbyname().
To access this functionality without the core overrides, pass the "use" an empty import list, and then access function functions with their
full qualified names. On the other hand, the built-ins are still available via the "CORE::" pseudo-package.
EXAMPLES
The getnet() functions do this in the Perl core:
sv_setiv(sv, (I32)nent->n_net);
The gethost() functions do this in the Perl core:
sv_setpvn(sv, hent->h_addr, len);
That means that the address comes back in binary for the host functions, and as a regular perl integer for the net ones. This seems a bug,
but here's how to deal with it:
use strict;
use Socket;
use Net::netent;
@ARGV = ('loopback') unless @ARGV;
my($n, $net);
for $net ( @ARGV ) {
unless ($n = getnetbyname($net)) {
warn "$0: no such net: $net
";
next;
}
printf "
%s is %s%s
",
$net,
lc($n->name) eq lc($net) ? "" : "*really* ",
$n->name;
print " aliases are ", join(", ", @{$n->aliases}), "
"
if @{$n->aliases};
# this is stupid; first, why is this not in binary?
# second, why am i going through these convolutions
# to make it looks right
{
my @a = unpack("C4", pack("N", $n->net));
shift @a while @a && $a[0] == 0;
printf " addr is %s [%d.%d.%d.%d]
", $n->net, @a;
}
if ($n = getnetbyaddr($n->net)) {
if (lc($n->name) ne lc($net)) {
printf " That addr reverses to net %s!
", $n->name;
$net = $n->name;
redo;
}
}
}
NOTE
While this class is currently implemented using the Class::Struct module to build a struct-like class, you shouldn't rely upon this.
AUTHOR
Tom Christiansen
perl v5.16.2 2012-08-26 Net::netent(3pm)