ascii lists ASCII idiomatic names and octal/decimal code-point forms. It provides easy conversion between various byte representations and the American Standard Code for Information Interchange (ASCII) character table. It knows about a wide variety of hex, binary, octal, Teletype mnemonic, ISO/ECMA code point, slang names, XML entity names, and other representations. Given any one on the command line, it will try to display all others. Called with no arguments, it displays a small, handy ASCII chart.
grepcidr can be used to filter a list of IP addresses against one or more Classless Inter-Domain Routing (CIDR) specifications, or arbitrary networks specified by an address range. As with grep, there are options to invert matching and load patterns from a file. grepcidr is capable of comparing thousands or even millions of IPs to networks with little memory usage and in reasonable computation time. It has endless uses in network software, including mail filtering and processing, network security, log analysis, and many custom applications.