mdw@git.distorted.org.uk Git - ssr/blob - StraySrc/Libraries/Sapphire/s/cmdLine

   1 ;
   2 ; cmdLine.s
   3 ;
   4 ; Command line parsing (MDW)
   5 ;
   6 ; © 1994-1998 Straylight
   7 ;
   8
   9 ;----- Licensing note -------------------------------------------------------
  10 ;
  11 ; This file is part of Straylight's Sapphire library.
  12 ;
  13 ; Sapphire is free software; you can redistribute it and/or modify
  14 ; it under the terms of the GNU General Public License as published by
  15 ; the Free Software Foundation; either version 2, or (at your option)
  16 ; any later version.
  17 ;
  18 ; Sapphire is distributed in the hope that it will be useful,
  19 ; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ; GNU General Public License for more details.
  22 ;
  23 ; You should have received a copy of the GNU General Public License
  24 ; along with Sapphire.  If not, write to the Free Software Foundation,
  25 ; 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  26
  27 ;----- Standard header ------------------------------------------------------
  28
  29                 GET     libs:header
  30                 GET     libs:swis
  31
  32 ;----- Main code ------------------------------------------------------------
  33
  34                 AREA    |Sapphire$$Code|,CODE,READONLY
  35
  36 ; --- cl_next ---
  37 ;
  38 ; On entry:     R0 == pointer to a command line string (ctrl terminated)
  39 ;               R1 == pointer to a buffer (may be equal to R0)
  40 ;
  41 ; On exit:      CS if another word found, and
  42 ;                 R0 == updated past next word
  43 ;                 R1 preserved, buffer filled with null terminated string
  44 ;                 R2 == pointer to terminating null character
  45 ;               else CC and
  46 ;                 R0 == pointer to terminating character
  47 ;                 R1 preserved, buffer preserved
  48 ;                 R2 corrupted
  49 ;
  50 ; Use:          Extracts the next word from a command line string.  If the
  51 ;               string is in a writable buffer, you can set R1 == R0 to
  52 ;               start with.  You can build up a C-like argv array like this:
  53 ;
  54 ;                       ; R0 == pointer to command line in writable buffer
  55 ;
  56 ;                               MOV     R1,R0
  57 ;                               ADR     R3,argv
  58 ;                               MOV     R4,#0
  59 ;                       loop    BL      cl_next
  60 ;                               MOVCC   R1,#0
  61 ;                               STR     R1,[R3],#4
  62 ;                               ADDCS   R4,#0
  63 ;                               BCS     loop
  64 ;
  65 ;                       ; R0-R3 corrupted
  66 ;                       ; R4 == argc
  67 ;
  68 ;               This routine will handle quoted strings, considering them
  69 ;               to be single arguments.  Either type of quote will do,
  70 ;               quote doubling is required to insert quotes in quoted
  71 ;               strings.
  72
  73                 EXPORT  cl_next
  74 cl_next         ROUT
  75
  76                 STMFD   R13!,{R1,R3,R14}        ;Save some registers
  77                 MOV     R2,R1                   ;Set up buffer pointer
  78                 MOV     R1,#0                   ;No quotes found yet
  79                 MOV     R3,#0                   ;Various flags:
  80                                                 ;  b0 == written a character
  81                                                 ;  b1 == currently in quotes
  82                                                 ;  b2 == just closed quotes
  83
  84                 ; --- Skip past leading spaces ---
  85
  86 00cl_next       LDRB    R14,[R0],#1             ;Load a byte from the string
  87                 CMP     R14,#' '                ;Is it a space?
  88                 CMPNE   R14,#9                  ;Or a tab will do too
  89                 BEQ     %00cl_next              ;Yes -- get another character
  90
  91                 ; --- Main character reading loop ---
  92
  93 10cl_next       CMP     R14,#' '                ;Is it the string end?
  94                 SUBLO   R0,R0,#1                ;Keep ptr at ctrl char
  95                 TSTEQ   R3,#2                   ;Are we currently in quotes?
  96                 BLS     %90cl_next              ;No -- deal with it nicely
  97
  98                 CMP     R14,R1                  ;Is it the last quote char?
  99                 BEQ     %30cl_next              ;Yes -- deal with this
 100
 101                 BIC     R3,R3,#4                ;Last one wasn't a quote
 102
 103                 CMP     R14,#'"'                ;Is it a double quote?
 104                 CMPNE   R14,#'''                ;Or a single one?
 105                 TSTEQ   R3,#2                   ;Make sure not in quoted
 106                 BEQ     %20cl_next              ;Yes -- deal with this then
 107
 108                 STRB    R14,[R2],#1             ;Otherwise store the byte
 109                 ORR     R3,R3,#1                ;Remember we've done it
 110                 LDRB    R14,[R0],#1             ;Load a byte from the string
 111                 B       %10cl_next              ;And go round again
 112
 113                 ; --- Handle a new quote character ---
 114
 115 20cl_next       MOV     R1,R14                  ;Remember the quote character
 116                 ORR     R3,R3,#2                ;We're now in quotes
 117                 LDRB    R14,[R0],#1             ;Load a byte from the string
 118                 B       %10cl_next              ;And go round again
 119
 120                 ; --- Handle a matched quote character ---
 121                 ;
 122                 ; Now this may be a close quote, or it may be a double quote
 123                 ; to indicate a literal.  We handle this by the following:
 124                 ;
 125                 ; if lastWasCloseQuotes
 126                 ;   write literal quote char
 127                 ;   set inQuotes
 128                 ;   clear lastWasCloseQuotes
 129                 ; else if inQuotes
 130                 ;   clear inQuotes
 131                 ;   set lastWasCloseQuotes
 132                 ; end
 133
 134 30cl_next       TST     R3,#6                   ;Was last quote, or inQuotes?
 135                 BEQ     %20cl_next              ;No -- then it's an open
 136                 TST     R3,#4                   ;Was last one a quote?
 137                 STRNEB  R14,[R2],#1             ;Yes -- then store quote
 138                 ORRNE   R3,R3,#1                ;Remember we store something
 139                 EOR     R3,R3,#6                ;And toggle the bits nicely
 140                 LDRB    R14,[R0],#1             ;Load a byte from the string
 141                 B       %10cl_next              ;Return to the loop
 142
 143                 ; --- We reached the end of the string ---
 144
 145 90cl_next       TST     R3,#1                   ;Did we write any text?
 146                 MOVNE   R14,#0                  ;A terminating null
 147                 STRNEB  R14,[R2],#0             ;If so, terminate the text
 148                 LDMFD   R13!,{R1,R3,R14}        ;Unstack the registers
 149                 ORRNES  PC,R14,#C_flag          ;If so, set C on exit
 150                 BICEQS  PC,R14,#C_flag          ;Otherwise clear C
 151
 152                 LTORG
 153
 154 ; --- cl_buildArgv ---
 155 ;
 156 ; On entry:     R0 == command line string (writable)
 157 ;               R1 == address of argv buffer
 158 ;
 159 ; On exit:      R1 == next unused location in argv buffer
 160 ;
 161 ; Use:          Turns the given string into an argv array which will make
 162 ;               argument scanning easier.  This is pretty much the code
 163 ;               given in the description of cl_next.
 164
 165                 EXPORT  cl_buildArgv
 166 cl_buildArgv    ROUT
 167
 168                 STMFD   R13!,{R0,R2,R3,R14}     ;Save some registers
 169                 MOV     R3,R1                   ;Move the argv address away
 170                 MOV     R1,R0                   ;Point to output buffer
 171
 172                 ; --- Copy the argument pointers over ---
 173
 174 00              BL      cl_next                 ;Fetch the next argument
 175                 MOVCC   R1,#0                   ;If done, null terminate list
 176                 STR     R1,[R3],#4              ;Store the pointer away
 177                 MOVCS   R1,R0                   ;More to come -- reset buffer
 178                 BCS     %b00                    ;And loop around
 179
 180                 ; --- Tidy up and leave ---
 181
 182                 SUB     R1,R3,#4                ;Point at terminating zero
 183                 LDMFD   R13!,{R0,R2,R3,PC}^     ;And return to caller
 184
 185                 LTORG
 186
 187 ; --- cl_getopt ---
 188 ;
 189 ; On entry:     R1 = pointer to
 190 ;
 191 ; On exit:
 192
 193
 194 ;----- That's all, folks ----------------------------------------------------
 195
 196                 END