Can someone show me this?
Oldbitcollector (Jeff)
Posts: 8,091
Now that I've got a handle on storing information from the keyboard, I'm attempting to figure out ways to manipulate it.
for Instance, if I store "type filename" into @command can someone show me how to strip the "type " off leaving
only the "filename" in @command?
It looks like I've got to dump everything after the space to get this right, but I haven't cracked it.
Thanks
Oldbitcollector
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Buttons . . . check. Dials . . . check. Switches . . . check. Little colored lights . . . check.
— Calvin, of 'Calvin and Hobbes.
for Instance, if I store "type filename" into @command can someone show me how to strip the "type " off leaving
only the "filename" in @command?
It looks like I've got to dump everything after the space to get this right, but I haven't cracked it.
Thanks
Oldbitcollector
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Buttons . . . check. Dials . . . check. Switches . . . check. Little colored lights . . . check.
— Calvin, of 'Calvin and Hobbes.
Comments
CON Cr = $0D ' New line / Return Lf = $0A ' Line feed Del = $7F ' Delete maxLine = 80 ' Maximum line / pattern length maxTime = 1000 ' Maximum time for response maxArb = 8 ' Maximum number of arbitrary strings matchArb = $0100 ' Match arbitrary string matchMax = matchArb + maxArb - 1 matchAny = $01FF ' Match any single character VAR long msTime ' Precomputed clkfreq / 1000 word pattern[noparse][[/noparse]maxLine] ' Work area for pattern match pattern byte line[noparse][[/noparse]maxLine] ' Input line buffer byte lineLen ' Current length of input line buffer byte patternLen ' Current length of pattern byte arbPtr[noparse][[/noparse]maxArb] ' Arbitrary string - pointer to buffer byte arbLen[noparse][[/noparse]maxArb] ' Arbitrary string - length of substring byte arbPos[noparse][[/noparse]maxArb] ' Arbitrary string - position in pattern byte arbCnt ' Number of arbitrary strings in pattern OBJ ser : "FullDuplexSerial" PUB start(TxD,RxD) msTime := clkfreq / 1000 ' Precompute system clocks per ms clearLine ' Initialize input line buffer ser.start(TxD,RxD,%0000,9600) ' Start the serial port PRI clearLine ' Clear input line lineLen := 0 PRI match(str,ptr,lenPtr,maxLen) | p, i, t, s, c, len, arb '' This routine matches the input line against a pattern supplied as a string. '' The pattern consists of characters and the metacharacters "*" and "?". '' The "\" character is an escape and the next byte is taken literally. '' Special cases include "\0" for a zero byte, "\r" for a carriage return, '' "\n" for a Unix newline (line feed), and "\d" for delete ($7F). '' "?" will match any single byte value. "*" will match any arbitrary string. '' These matches are recorded in arbPtr and arbLen as index and length of the '' matched substring in the input. This routine returns true if successful '' and false if there's no match. The match algorithm works by extending the '' last "*" to the first substring that produces a match. If the input line '' is not long enough for the match, this routine attempts to read additional '' characters from the serial (FullDuplexSerial) driver with a total timeout '' defined by the constant maxTime. '' str is the address of the pattern, a zero terminated string. '' ptr is the address of the input line buffer '' lenPtr is the address of a byte containing the length of the input line '' maxLen is the allocated size of the input line buffer patternLen := 0 ' Anchor on left to start of line arbCnt := 0 repeat ' Go through pattern string case p := byte[noparse][[/noparse]str++] 0: quit ' End of pattern string "*": ' Match arbitrary string arbLen[noparse][[/noparse]arbCnt] := 0 arbPos[noparse][[/noparse]arbCnt] := patternLen pattern[noparse][[/noparse]patternLen++] := matchArb + arbCnt++ "\": ' Escape any byte value case p := byte[noparse][[/noparse]str++] 0: quit ' Ignore if at end of pattern "0": p := 0 ' Substitute a zero byte "r": p := Cr ' Substitute a return character "n": p := Lf ' Substitute a line feed character "d": p := Del ' Substitute a delete character pattern[noparse][[/noparse]patternLen++] := p "?": ' Match any single character pattern[noparse][[/noparse]patternLen++] := matchAny other: ' Any other, take literally pattern[noparse][[/noparse]patternLen++] := p p := 0 i := 0 arb := -1 len := byte[noparse][[/noparse]lenPtr] t := cnt repeat ' Go back and forth through pattern if p == patternLen if i == len ' At end of pattern, have we matched return true ' the whole input line? if arb < 0 ' Can we extend the last arbitrary return false ' string to get a complete match? p := arbPos[noparse][[/noparse]arb] i := arbPtr[noparse][[/noparse]arb] arbLen[noparse][[/noparse]arb]++ case s := pattern[noparse][[/noparse]p++] matchArb..matchMax: ' Going forward through arbitrary arb := s - matchArb ' string, just skip over text arbPtr[noparse][[/noparse]arb] := i i += arbLen[noparse][[/noparse]arb] matchAny: ' Going forward through arbitrary if i++ == len ' single character. Check length if len == maxLen return false repeat while (c := ser.rxcheck) < 0 if (cnt - t) => msTime * maxTime return false byte[noparse][[/noparse]lenPtr]++ ' Increment text buffer size byte[noparse][[/noparse]ptr][noparse][[/noparse]len++] := c ' and save the character other: ' Going forward through a literal if i == len ' character, check max length if len == maxLen return false repeat while (c := ser.rxcheck) < 0 if (cnt - t) => msTime * maxTime return false byte[noparse][[/noparse]lenPtr]++ ' Increment text buffer size byte[noparse][[/noparse]ptr][noparse][[/noparse]len++] := c ' and save the character if s <> byte[noparse][[/noparse]ptr][noparse][[/noparse]i++] ' then check for a match if arb < 0 ' See if we can extend the previous return false ' arbitrary string to get a match p := arbPos[noparse][[/noparse]arb] ' Extend current arbitrary string i := arbPtr[noparse][[/noparse]arb] ' and try to match again arbLen[noparse][[/noparse]arb]++Desilva: Yes, I'm starting to see the similarities to C in spin. That's practical advice.
Actually, I'm pretty close to a working solution. If I use @buffer[noparse][[/noparse]#] I could grab each
character of the part I need since I know where the starting position is in each command.
Not a pretty solution, but one I can understand at the level I'm at.
Now that I've gotten my mind wrapped around some of the concepts of byte,and case
(which kept going right over my head initially) The section in the manual for .spin
commands is starting to make sense. There is a real gap that has to be crossed for
someone like myself with limited experience in object-oriented programming.
One of the walls I ran into early with the Propeller is that there is an assumption
of experience in with other micros when starting with the Propeller, a wall
I've been chipping away 'hardware-wise' with the Cookbook.
I'm still building the foundation for a text called ".spin for BASIC programmers"
Perhaps I can bridge this learning gap for others.
Oldbitcollector
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Buttons . . . check. Dials . . . check. Switches . . . check. Little colored lights . . . check.
— Calvin, of 'Calvin and Hobbes.
Mike, how's the flux_capacitor.spin program coming along?
Gr,
Mightor
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| To know recursion, you must first know recursion.
| I reject your reality and substitute my own!
| - Adam Savage
[noparse];)[/noparse]
Oldbitcollector
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Buttons . . . check. Dials . . . check. Switches . . . check. Little colored lights . . . check.
— Calvin, of 'Calvin and Hobbes.
BTW, my vinculum host responses are already in stuffed into a LockPool, so I'll be modifying Mike's code to work from there. If anyone else wants a version that reads from a memory pool stay tuned and I'll post the code here.