161 lines
4.9 KiB
Plaintext
161 lines
4.9 KiB
Plaintext
-*- outline -*-
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scsh-yp 0.1
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* Introduction
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Scsh-yp is a package for scsh, the Scheme shell[1] that provides
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bindings to the YP/NIS functions. This enables the scsh user to
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lookup data in a NIS or YP database without calling the
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corresponding external program (i. e. ypbind, ypmatch etc).
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* Using scsh-yp
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** yp-error condition hierarchy
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Scsh-yp uses scsh's condition system to signal exceptions. In this
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system conditions are organized hierarchially. Use one of the
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following predicates to check what kind of error occurred:
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yp-error?
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+-- yp-communication-error?
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| |
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| +-- yp-bad-domain?
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| +-- yp-no-domain?
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| +-- yp-portmap-failure?
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| +-- yp-rpc-failure?
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| +-- yp-bind-failure?
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| +-- yp-binding-error?
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| +-- yp-server-error?
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+-- yp-bad-arguments?
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+-- yp-bad-database?
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+-- yp-unknown-resource-error?
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| |
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| +-- yp-unknown-key?
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| +-- yp-unknown-map?
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+-- yp-internal-error?
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These errors correspond to the return codes of C yp_*() function
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calls. The yp_* man pages explain the error codes in detail.
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** function reference
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This sections gives an brief overview on the functions provided by
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the scsh-yp package. The man pages of the underlying yp_*()
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function calls explain these functions in greater detail. Almost
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all of the functions listed here have an optional parameter DOMAIN
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that tells YP/NIS which YP/NIS domain you are referring to. If
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this parameter is omitted, the default domain will be used, that
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is, the domain name that can be obtained with
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YP-GET-DEFAULT-DOMAIN.
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(yp-get-default-domain) -> string
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Returns the default YP/NIS domain.
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(yp-bind [domain]) -> #t
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Connect and use to the YP/NIS domain DOMAIN. Returns #t on success
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or raises a yp-error condition.
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(yp-unbind [domain]) -> #t
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Unbind from the domain DOMAIN. Returns #t on success or raises a
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yp-error condition.
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(yp-match map key [domain]) -> list-of-strings
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Returns the entries in MAP (a string) that match KEY (a string).
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Make sure to use a full NIS/YP map name, e.g. "passwd.byname"
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instead of "passwd". May raise an yp-error condition.
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(yp-order map [domain]) -> integer
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Returns the order number of a MAP (a string). May raise an yp-error.
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(yp-master map [domain]) -> string
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Returns the master server that serves MAP (a string). May raise an
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yp-error.
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(yp-first map [domain]) -> {string string}
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(yp-next map key [domain]) -> {string-or-bool string-or-bool}
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Use YP-FIRST and YP-NEXT to step through all entries of MAP (a
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string). YP-FIRST returns two strings: The key and the complete
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map entry for that key. To obtain the next value(s) in the map
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call YP-NEXT with the key. If YP-NEXT hits the end of the map it
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returns {#f #f}. Both functions may raise an yp-error.
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(yp-map->list map [domain]) -> list-of-pairs
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Reads all entries from a YP/NIS MAP (a string) and return them as a
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list of pairs. The CAR of each pair is the key of the entry, the
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CDR contains the complete entry. May raise an yp-error.
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** Examples
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Using yp-first and yp-next to obtain a list of all keys in the map
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passwd.byname (uses RECEIVE from SRFI 8):
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,----
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| define (yp-all-keys map domain)
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| (receive (key val) (yp-first map domain)
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| (let loop ((key key) (res (cons key '())))
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| (receive (key val)
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| (yp-next map key domain)
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| (if val
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| (loop key (cons key res))
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| res)))))
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| > (yp-all-keys "passwd.byname" "wsi")
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| (... very long list ...)
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`----
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Searching for an entry in passwd.byname an parsing the result:
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,----
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| (define (yp-account-data user)
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| (let ((splitter (infix-splitter (rx ":"))))
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| (cond ((yp-match "passwd.byname" user)
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| => splitter)
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| (else #f))))
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| > (yp-account-data "knauel")
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| '("knauel" "geheim" "5324" "3010" "Eric Knauel"
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| "/afs/informatik.uni-tuebingen.de/home/knauel" "/bin/tcsh")
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| > (yp-account-data "klabautermann")
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| Error: yp-unknown-key
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| 5
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| (yp-match map "passwd.byname" key "klabautermann" domain ---)
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| 1>
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`----
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* Caveats
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There is only a synchronous high-level interface to YP/NIS, so
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calling a yp_*() function causes scsh and all scsh threads to block.
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I hope to solve that problem in a future version of scsh-yp.
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* Bug reporting
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Please report bugs to <scsh-bugs@zurich.ai.mit.edu>.
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* Version history
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Mar 2004: released 0.2
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Dec 2003: released 0.1
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* Acknowlegdements
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I would like to thank Martin Gasbichler who was fearless enough to
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engage in a battle with automake and wrote the automake build
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files.
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Eric Knauel
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<knauel@informatik.uni-tuebingen.de>
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T<>bingen, December 2003
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Footnotes:
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[1] <http://www.scsh.net/>
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