Projects / netcat

netcat

Netcat is a simple Unix utility which reads and writes data across network connections, using TCP or UDP protocol. It is designed to be a reliable backend tool that can be used directly or easily driven by other programs time, it is a feature-rich network debugging and exploration tool, since it can create almost any kind of connection you would need and has several interesting built-in capabilities.

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  •  26 Nov 2004 11:09

    Release Notes: This release fixes several bugs in IPv6 handling and reintroduces host names (reverse-resolved using the getnameinfo function) in verbose messages, which were disabled until now. The argument to -q now works as advertised. It also improves portability.

    •  28 Jun 2003 19:04

      Release Notes: This release fixes a bug in which only 8k of the data to be sent to the remote host was accepted.

      •  01 Jun 2003 14:41

        Release Notes: This release cleans up the code in netcat 1.10, modernizes some things (including support for IPv6), and has some popular patches, including those that Debian uses for its own netcat. It does not do reverse DNS lookups anymore, but this is only temporary. Instead, source routing has been removed because nobody leaves it enabled anymore. autoconf is now used.

        Recent comments

        26 Nov 2004 02:14 bonzini

        Re: IPv6 Port


        > Change USHRT_MAX to 65535, then compile.

        > Works like a charm.

        Or include limits.h. Silly me.

        28 Sep 2003 15:29 QuiGonGene

        IPv6 Port
        I had a problem compiling the IPv6 version on FreeBSD 5.0. Changed the following to make it work:

        first_port = strtoul (argv[optind], &tail, 0);
        if (first_port > USHRT_MAX || *tail || first_port == 0)
        bail ("invalid port %s", argv[optind]);

        last_port = strtoul (cp, &tail, 0);
        if (last_port > USHRT_MAX || *tail || last_port == 0)
        bail ("invalid port %s", cp);

        Change USHRT_MAX to 65535, then compile. Works like a charm.

        18 Sep 2003 02:16 FisherKing

        Re: Compile error

        >
        > % When I compile netcat on Linux it gives
        > % me this errors:
        > %
        > % /tmp/cccUSCm5.o: In function `main':
        > % /tmp/cccUSCm5.o(.text+0x1b1a): undefined
        > % reference to `res_init'
        > % collect2: ld returned 1 exit status
        > %
        >
        >
        > Check the comments a little down the
        > page titled 'compile for linux.' The
        > error you mention goes away by adding
        > 'include resolv.h' to netcat.c
        >


        The debian guys have a whole bunch of patches for netcat
        get ftp://ftp.debian.org/debian/pool/n/netcat/netcat_1.10-23.diff.gz

        installation, in netcat dir:

        zcat ~/src/netcat_1.10-23.diff.gz | patch

        for i in `cat 00list` ; do cat $i.dpatch | patch;done

        04 Jul 2003 12:28 jbarchuk

        Re: Compile error

        > When I compile netcat on Linux it gives
        > me this errors:
        >
        > /tmp/cccUSCm5.o: In function `main':
        > /tmp/cccUSCm5.o(.text+0x1b1a): undefined
        > reference to `res_init'
        > collect2: ld returned 1 exit status
        >


        Check the comments a little down the page titled 'compile for linux.' The error you mention goes away by adding 'include resolv.h' to netcat.c

        05 Jun 2003 02:50 netAGENT

        Compile error
        When I compile netcat on Linux it gives me this errors:

        /tmp/cccUSCm5.o: In function `main':
        /tmp/cccUSCm5.o(.text+0x1b1a): undefined reference to `res_init'
        collect2: ld returned 1 exit status

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