string splitting problem

[Robert L.]

Pascal Bourguignon wrote:

> > I have to split a string from /proc/net/arp of the format
> > "127.0.0.1 0x1 0x2 00:11:22:33:AE:5E * ethx"
> > ^^^
> > to extract the MAC.
>
>
> When I don't need the utmost efficient solution, I merely use:
>
> [69]> (split-string (fourth (delete "" (split-string line " ")
> :test (function string=))) ":")
> ("00" "11" "22" "33" "AE" "5E")
>
>
> with (GPL sources):
>
> (DEFUN SPLIT-STRING (STRING &OPTIONAL (SEPARATORS " "))
> "
> NOTE: current implementation only accepts as separators
> a string containing literal characters.
> "
> (UNLESS (SIMPLE-STRING-P STRING) (SETQ STRING (COPY-SEQ STRING)))
> (UNLESS (SIMPLE-STRING-P SEPARATORS) (SETQ SEPARATORS (COPY-SEQ SEPARATORS)))
> (LET ((CHUNKS '())
> (POSITION 0)
> (NEXTPOS 0)
> (STRLEN (LENGTH STRING)) )
> (DECLARE (TYPE SIMPLE-STRING STRING SEPARATORS))
> (LOOP WHILE (< POSITION STRLEN)
> DO
> (LOOP WHILE (AND (< NEXTPOS STRLEN)
> (not (position (CHAR STRING NEXTPOS) separators)))
> DO (SETQ NEXTPOS (1+ NEXTPOS))
> );;loop
> (PUSH (SUBSEQ STRING POSITION NEXTPOS) CHUNKS)
> (SETQ POSITION (1+ NEXTPOS))
> (SETQ NEXTPOS POSITION)
> );;loop
> (NREVERSE CHUNKS)
> );;let
> );;SPLIT-STRING

(define (split-string str (separators " "))
(define seps (string->list separators))
(define strlen (string-length str))
(let loop ((i 0) (anchor 0) (chunks '()))
(cond ((= i strlen) (reverse (cons (substring str anchor i) chunks)))
((member (string-ref str i) seps)
(loop (+ i 1) (+ i 1) (cons (substring str anchor i) chunks)))
(else (loop (+ i 1) anchor chunks)))))

(require srfi/1) ; delete

(define line
"127.0.0.1 0x1 0x2 00:11:22:33:AE:5E * ethx")

(split-string (fourth (delete "" (split-string line))) ":")

===>
("00" "11" "22" "33" "AE" "5E")

In Forth?

--
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refused to take any Syrian refugees. "We will not allow Israel to be submerged
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said. http://archive.org/details/nolies

[Bob Armstrong]

How's this . In CoSy :
s" 127.0.0.1 0x1 0x2 00:11:22:33:AE:5E * ethx" >t0
t0 "bl VM dae 3 _at s" :" VM

(
00
11
22
33
AE
5E
)

Here are the non-obvious words :

s" : VM " ??
: tokcut ( str tok -- CV ) | cuts string at occurances of string `tok but includes segment before first token
2p LR@ css i0 swap ,I L@ swap cut 2P> ;

: VM : toksplt ( str tok -- CV ) | like ' tokcut but deletes the tokens from the cut pieces
| cr ." toksplt " ( 2p> tokcut i0 R@ rho )
2p LR@ swap cL >aux+> dup R@ css cut | appends
aux- R@ rho ['] cut eachleft 2P> ;

s" : dae " ??
: dae ( v -- v ) >aux+> dup ['] rho 'm ,/ i0 <>i & at aux- ;
| Delete All Empties . Deletes all empty , items of a list .
| translated from K | { x @ & 0 < #:' x } |

--
On Monday, November 13, 2017 at 11:51:23 AM UTC-7, Robert L. wrote:

[Ala'a]

Just for fun. This solution is not tested and assumes a couple of things. This
is just for solving the given string sample:

: SPF4 /tmp/mac.f
0 11 22 33 AE 5E


\ mac.f
\ Given buffer address, return address of first letter after SPACE
: 'BL+ ( a - 'bl+) BEGIN DUP C@ BL <> WHILE 1+ REPEAT 1+ ;

\ Given buffer address, read 2 digit number and return next address and number
: ##: ( a1 - a2 u) 0 0 ROT 2 >NUMBER DROP 1+ NIP SWAP ;

\ Given buffer address which contains a line formatted as
\ "nnn.nnn.nnn.nnn 0xn 0xn xx:xx:xx:xx:xx:xx if" print the hardward address
: .MAC ( a - ) 'BL+ 'BL+ 'BL+ ##: . ##: . ##: . ##: . ##: . ##: . DROP ;

S" 127.0.0.1 0x1 0x2 00:11:22:33:AE:5E * ethx" DROP HEX .MAC BYE