Scsh (a ''Scheme shell'') is computer

software Software is a set of computer programs and associated software documentation, documentation and data (computing), data. This is in contrast to Computer hardware, hardware, from which the system is built and which actually performs the work. ...

, a type of

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

for an

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also i ...

. It is a Portable Operating System Interface (

POSIX The Portable Operating System Interface (POSIX) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines both the system- and user-level application programming inter ...

) application programming interface (API) layered on the programming language Scheme, in a manner to make the most of Scheme's ability for scripting. Scsh is limited to 32-bit platforms but there is a development version against the latest

Scheme 48 Scheme 48 is a programming language, a dialect of the language Scheme, an implementation using an interpreter which emits bytecode. It has a foreign function interface for calling functions from the language C and comes with a library for reg ...

that works in

64-bit In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit CPUs and ALUs are those that are based on processor registers, address buses, or data buses of that size. A compu ...

mode. It is free and open-source software released under the BSD-3-Clause license.

Features

Scsh includes these notable features: *

Library A library is a collection of materials, books or media that are accessible for use and not just for display purposes. A library provides physical (hard copies) or digital access (soft copies) materials, and may be a physical location or a vir ...

support for list, character, and string manipulations; *

Regular expression A regular expression (shortened as regex or regexp; sometimes referred to as rational expression) is a sequence of characters that specifies a search pattern in text. Usually such patterns are used by string-searching algorithms for "find" ...

s manipulation support using ''scheme regular expressions'', a domain-specific language (DSL), or little languages, approach to the abilities; * Strong networking support; * High-level support for

awk AWK (''awk'') is a domain-specific language designed for text processing and typically used as a data extraction and reporting tool. Like sed and grep, it is a filter, and is a standard feature of most Unix-like operating systems. The AWK lang ...

like scripts, integrated into the language as macros; * Abstractions supporting

pseudo terminal In some operating systems, including Unix and Linux, a pseudoterminal, pseudotty, or PTY is a pair of pseudo-device endpoints (files) which establish asynchronous, bidirectional communication ( IPC) channel (with two ports) between two or more pr ...

s; * A

language, modeled using

quasi-quotation Quasi-quotation or Quine quotation is a linguistic device in formal languages that facilitates rigorous and terse formulation of general rules about linguistic expressions while properly observing the use–mention distinction. It was introduced ...

Example

* Print a list of all the executables available in the current

PATH A path is a route for physical travel – see Trail. Path or PATH may also refer to: Physical paths of different types * Bicycle path * Bridle path, used by people on horseback * Course (navigation), the intended path of a vehicle * Desire p ...

to the

standard output In computer programming, standard streams are interconnected input and output communication channels between a computer program and its environment when it begins execution. The three input/output (I/O) connections are called standard input (stdin ...

: #!/usr/local/bin/scsh -s !# (define (executables dir) (with-cwd dir (filter file-executable? (directory-files dir #t)))) (define (writeln x) (display x) (newline)) (for-each writeln (append-map executables ((infix-splitter ":") (getenv "PATH"))))

"Acknowledgments"

The reference manual for Scsh includes a spoof Acknowledgments section written by Olin Shivers. It starts: :''Who should I thank? My so-called "colleagues", who laugh at me behind my back, all the while becoming famous on my work? My worthless graduate students, whose computer skills appear to be limited to downloading bitmaps off of netnews? My parents, who are still waiting for me to quit "fooling around with computers," go to med school, and become a radiologist? My department chairman, a manager who gives one new insight into and sympathy for disgruntled postal workers?'' and concludes with: :''Oh, yes, the acknowledgements. I think not. I did it. I did it all, by myself.''

References

External links

* *
Sourceforge project page
Unix shells Scheme (programming language) interpreters Scheme (programming language) implementations Scripting languages Software using the BSD license {{Unix-stub

Features

Example

"Acknowledgments"

See also

References

External links