Sponsored Content
Full Discussion: ARGV how to use it?
Top Forums UNIX for Dummies Questions & Answers ARGV how to use it? Post 302967866 by drl on Monday 29th of February 2016 11:38:16 AM
Old 02-29-2016
Hi.

I usually look at perldoc perlvar for questions like this. In this case:
Code:
    $ARGV   Contains the name of the current file when reading from "<>".

    @ARGV   The array @ARGV contains the command-line arguments intended for
            the script. $#ARGV is generally the number of arguments minus one,
            because $ARGV[0] is the first argument, not the program's command
            name itself. See "$0" for the command name.

    ARGV    The special filehandle that iterates over command-line filenames
            in @ARGV. Usually written as the null filehandle in the angle
            operator "<>". Note that currently "ARGV" only has its magical
            effect within the "<>" operator; elsewhere it is just a plain
            filehandle corresponding to the last file opened by "<>". In
            particular, passing "\*ARGV" as a parameter to a function that
            expects a filehandle may not cause your function to automatically
            read the contents of all the files in @ARGV.

Best wishes ... cheers, drl
This User Gave Thanks to drl For This Post:
 

10 More Discussions You Might Find Interesting

1. Programming

argv

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)
Discussion started by: mbb
2 Replies

2. Programming

Using argv argc

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)
Discussion started by: Akeson Chihiro
4 Replies

3. Shell Programming and Scripting

Perl: Getting $ARGV's to operate like while(<>)

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)
Discussion started by: jjinno
2 Replies

4. Programming

help for argv argc

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)
Discussion started by: return_user
5 Replies

5. Shell Programming and Scripting

if #argv = (this OR that) then...

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)
Discussion started by: ajp7701
5 Replies

6. Shell Programming and Scripting

$#Argv in Csh

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)
Discussion started by: new2C
1 Replies

7. Programming

ARGV help in C

Hi, Can somehelp help how to list file in a dir? (5 Replies)
Discussion started by: Learnerabc
5 Replies

8. Programming

help with C, argv

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)
Discussion started by: omega666
2 Replies

9. Programming

How do I copy or rewind *argv[]

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)
Discussion started by: Errigour
16 Replies

10. UNIX for Advanced & Expert Users

O argv, argv, wherefore art thou argv?

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
Net::hostent(3pm)					 Perl Programmers Reference Guide					 Net::hostent(3pm)

NAME
Net::hostent - by-name interface to Perl's built-in gethost*() functions SYNOPSIS
use Net::hostent; DESCRIPTION
This module's default exports override the core gethostbyname() and gethostbyaddr() functions, replacing them with versions that return "Net::hostent" objects. This object has methods that return the similarly named structure field name from the C's hostent structure from netdb.h; namely name, aliases, addrtype, length, and addr_list. The aliases and addr_list methods return array reference, the rest scalars. The addr method is equivalent to the zeroth element in the addr_list array reference. 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 "h_". Thus, "$host_obj->name()" corresponds to $h_name if you import the fields. Array references are available as regular array variables, so for example "@{ $host_obj->aliases() }" would be simply @h_aliases. The gethost() function is a simple front-end that forwards a numeric argument to gethostbyaddr() by way of Socket::inet_aton, and the rest to gethostbyname(). 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
use Net::hostent; use Socket; @ARGV = ('netscape.com') unless @ARGV; for $host ( @ARGV ) { unless ($h = gethost($host)) { warn "$0: no such host: $host "; next; } printf " %s is %s%s ", $host, lc($h->name) eq lc($host) ? "" : "*really* ", $h->name; print " aliases are ", join(", ", @{$h->aliases}), " " if @{$h->aliases}; if ( @{$h->addr_list} > 1 ) { my $i; for $addr ( @{$h->addr_list} ) { printf " addr #%d is [%s] ", $i++, inet_ntoa($addr); } } else { printf " address is [%s] ", inet_ntoa($h->addr); } if ($h = gethostbyaddr($h->addr)) { if (lc($h->name) ne lc($host)) { printf " That addr reverses to host %s! ", $h->name; $host = $h->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 v5.16.3 2013-02-26 Net::hostent(3pm)
All times are GMT -4. The time now is 08:04 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy