Single File Tools (SFT)

This repository collects a couple of simple utilities written in different languages for varying use cases. The single common factor is an implementation comprising just one file. These single file tools are usually written in an interpreted (or scripting) language.

All single file tools are intended to be usable without installation. I usually check out this repository on every machine I work with. If one of the tools needs to be started from a specific directory that is a bug.

License

All tools contain licensing information in the file. In general, every tool is published under a free software license. Additionally, this collection is available under the GNU General Public License version 3 or later.

The Tools

Some of the single file tools have been published already using a dedicated web page. In that case a link to the web page is provided.

Documentation

If a dedicated web page for a single file tool exists, it contains documentation for the specific tool. Additionally, since all tools are comprised of a single file, their documentation, as far as it exists, is part of the program itself.

All tools are scripts for some interpreter, thus they can be viewed with any text viewer, e.g., a pager or an editor. Usually the documentation is included as a comment after the copyright statement.

Sometimes the tool supports a -h option to show help.

Sometimes, if the tool is not a filter, it prints out a help screen if called without any operands (neither options nor arguments).

Some of the tools complement each other. E.g., ping_wrapper allows using ping_scan on GNU/Linux, and net2ips uses ipcalc, either https://jodies.de/ipcalc or the ipcalc script from this collection.

List of Single File Tools

• archive_url - archive the given URLs in the Wayback Machine, unless they are already archived there
• capture.sh - capture traffic on an interface for a given duration with tcpdump
• checkzips - check ZIP files for errors
• create_ipv6_ULA_global_prefix_random.sh - create a random global prefix for IPv6 ULA addresses using /dev/random
• create_ipv6_ULA_global_prefix_rfc4193.sh - create a pseudo random global prefix for IPv6 ULA addresses using a deterministic algorithm based on RFC 4193 section 3.2.2
• dvdmovie - play the main movie from a video DVD with MPlayer (web page)
• enclosing-section - print all enclosing sections containing a line matching a regular expression (inspired by the Huawei VRP output modifier section include; see my more featureful Go implementation of section as well)
• ensure_bom_crlf - Prepare a UTF-8 encoded POSIX text file for use on Windows by ensuring it starts with the UTF-8 encoded unicode code point U+FEFF "zero-width no-break space" (the old UCS-2 byte order mark (BOM)), and uses the CR LF ("\r\n") end-of-line character sequence
• ext_ip - print externally visible IPv4 and IPv6 addresses
• ffdl - simple download helper for Firefox
• foreachpam - invoke program for each image in a PAM stream (web page)
• foreachpnm - invoke program for each image in a PNM stream (web page)
• hide_passwords_enterasys.sed - mask passwords in Enterasys (now Extreme) EOS configuration (available on my Notes on Enterasys Networks Equipment web page)
• ifstats - print interface statistics (counters) on Linux (uses sysfs)
• interface_status - query interface status of network devices via SNMP
• intf_names - print interface names on Linux (uses sysfs)
• ipcalc - simple replacement for the jodies.de IP Calculator of the same name
• ipenum.py - enumerate IPv4 and IPv6 addresses from the given ranges; ranges can be specified via start and end addresses, or in CIDR notation (implemented in Python 3 based on the Python standard library (stdlib) modules ipaddress and re)
• isascii - check if all input bytes contain 7-bit ASCII values
• macfmt - convert MAC address formats (web page)
• macfmt.py - alternative to the above macfmt, implemented in Python instead of Awk (mentioned on the macfmt web page)
• net2ips - print host addresses of an IPv4 network (uses ipcalc)
• net2ips.py - print addresses of IPv4 and IPv6 networks given in CIDR notation, implemented in Python 3 based on the Python standard library (stdlib) module ipaddress
• netio-kshell-dos - demonstrate TCP session cleanup bug (web page)
• nfoview - view NFO files on GNU/Linux
• ping_scan - ping many hosts at once (web page)
• ping_wrapper - wrapper around iputils ping for use with ping_scan (web page)
• pmtud - Path MTU discovery to given IP / HOSTNAME using ICMP Echo Request probes
• pnmcat-stream - wrapper for pnmcat to work with image streams (web page)
• priv_pass.py - calculate ROMMON priv password for (some) Cisco routers
• renumber - renumber a set of discontiguously numbered files
• rfc-reader - read IETF RFCs and I-Ds on GNU/Linux (web page)
• section - print all lines matching a regular expression, and the following indented section (inspired by the Cisco IOS output modifier of the same name) (see my more featureful Go implementation of section as well)
• section.pl - Perl version of the above section script, for use on systems without Awk, but Perl, such as some Cisco IOS XR versions (see my more featureful Go implementation of section as well)
• section.py - Python version of the above section script, for use on systems without Awk or Perl, but Python (see my more featureful Go implementation of section as well)
• slatel - strip leading and trailing empty lines
• thotp.py - compute one-time passwords using the HOTP (RFC 4226) or TOTP (RFC 6238) algorithms
• top-level-section - print all top-level sections containing a line matching a regular expression (inspired by the Arista EOS output modifier section; see my more featureful Go implementation of section as well)
• total_video_duration - print total run time of given video files (uses ffprobe from FFmpeg)
• vevent_dump - print a somewhat readable version of the essential information inside an iCalendar (.ics) file to STDOUT (best effort only, not even trying to parse the format...)
• vrp_output_to_yaml.awk - convert log from command execution on Huawei VRP device into YAML encoded list of dictionaries each comprising an executed command and its output

Junkcode

If you do not find what you are looking for in this repository, you might find example code licensed under the GNU Public License version 3 or later in my junkcode repository.

Homepage

For more of my work you can visit my homepage at the Unix-AG of the TU Kaiserslautern.