workbench/c/shellcommands/Cut.c

   1 /*
   2     Copyright © 2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: English
   7 */
   8
   9 /******************************************************************************
  10
  11     NAME
  12
  13         Cut
  14
  15     TEMPLATE
  16
  17         STRING/A,C=CHAR/K,W=WORD/K,S=SEPARATOR/K
  18
  19     LOCATION
  20
  21         SYS:C
  22
  23     FUNCTION
  24
  25         Extracts some characters or words from a string.
  26
  27     FORMAT
  28
  29         CUT <string> [CHAR <range> | WORD <range> [SEPARATOR <string>] ]
  30
  31     RESULT
  32
  33         Standard DOS return codes.
  34
  35     NOTES
  36
  37         Both  CHAR  (character)  and WORD arguments allow to define a begin and an end
  38         position  in the original string. Words are strings separated by a SEPARATOR (a
  39         space character (" ") is the default), which can also be a string.
  40
  41         Positions  range  is specified using numbers with the form "P1-P2", where "P1"
  42         is  the position of the first character (resp. word) to extract in the original
  43         string, "-" is the hyphen-minus character, and "P2" is the position of the last
  44         character (resp. word) to extract.
  45
  46         If  only  one  position  is  supplied, then only one character (resp. word) is
  47         extracted,  unless  the  hyphen-minus  character is supplied too: P- extracts a
  48         string  begining  at  the  character (resp. word) at position P in the original
  49         string until the end, and -P extracts a string starting at the beginning of the
  50         original  string,  and  ending with the character (resp. word) at position P in
  51         the original string.
  52
  53     EXAMPLES
  54
  55         Example 1:
  56         > Cut "A dummy sentence" CHAR 7
  57         y
  58         extract one character.
  59
  60         Example 2:
  61         > Cut "A dummy sentence" CHAR 6-12
  62         my sent
  63         extract from character 6 to 12.
  64
  65         Example 3:
  66         > Cut "A dummy sentence" CHAR -7
  67         A dummy
  68         extract from character 1 to 7 without specifying the beginning position.
  69
  70         Example 4:
  71         > Cut "A dummy sentence" CHAR 12-
  72         tence
  73         extract from character 12 of the string until the end.
  74
  75         Example 5:
  76         > Cut "A dummy sentence" WORD 2 SEPARATOR "en"
  77         t
  78         extract the second word (using an user-defined separator).
  79
  80
  81 ******************************************************************************/
  82
  83 #include <proto/exec.h>
  84 #include <proto/dos.h>
  85
  86 //#define DEBUG 1
  87 #include <aros/debug.h>
  88
  89 #include <aros/shcommands.h>
  90
  91 #define min(x,y) (((x) < (y)) ? (x) : (y))
  92 #define max(x,y) (((x) > (y)) ? (x) : (y))
  93
  94 struct Bounds
  95 {
  96     LONG Start;
  97     LONG End;
  98 };
  99
 100
 101 static struct Bounds *getBoundaries(STRPTR String, APTR DOSBase, struct ExecBase *SysBase);
 102
 103 AROS_SH4H(Cut,50.1, "extract some characters or words from a string\n",
 104 AROS_SHAH(STRPTR,  ,STRING   ,/A,NULL,"Quoted string from which to extract CHARacters or WORDs"),
 105 AROS_SHAH(STRPTR,C=,CHAR     ,/K,NULL,"Extract one or a range of characters, form is P1-P2"),
 106 AROS_SHAH(STRPTR,W=,WORD     ,/K,NULL,"Extract one or a range of words separated by SEPARATOR"),
 107 AROS_SHAH(STRPTR,S=,SEPARATOR,/K," " ,"Specify a string of any length to be used to split\n"
 108                                   "\t\tthe original STRING in WORDs (default: space character)"
 109
 110                              "\n\nExample: extract from character 6 to 12:\n"
 111                                  "> Cut \"A dummy sentence\" CHAR 6-12\n"
 112                                  "my sent\n") )
 113 {
 114     AROS_SHCOMMAND_INIT
 115
 116     int  rc    = RETURN_FAIL;
 117     LONG ioerr, stringLen, sepLen, wordCnt = 0;
 118     struct Bounds *charBounds, *wordBounds;
 119     STRPTR stringBuf = SHArg(STRING), sepBuf;
 120
 121     if (!SHArg(CHAR) && !SHArg(WORD))
 122         SetIoErr(ERROR_BAD_TEMPLATE);
 123
 124     stringLen = strlen((char *)SHArg(STRING));
 125     sepLen = strlen((char *)SHArg(SEPARATOR));
 126
 127     if (SHArg(WORD))
 128     {
 129         if ((wordBounds = getBoundaries(SHArg(WORD), DOSBase, SysBase)) != NULL)
 130         {
 131             if (0 != wordBounds->Start)
 132             {
 133                 wordCnt = wordBounds->Start - 1;
 134                 while (wordCnt && (sepBuf = (STRPTR)strstr((char *)stringBuf, (char *)SHArg(SEPARATOR))))
 135                 {
 136                     stringBuf = sepBuf + sepLen;
 137                     wordCnt--;
 138                 }
 139             }
 140
 141             if (0 == wordCnt)
 142             {
 143                 if (wordBounds->End)
 144                     wordCnt = wordBounds->End - (wordBounds->Start ? wordBounds->Start : 1) + 1;
 145                 else
 146                     /* Make sure to reach the end of the string in any case */
 147                     wordCnt = strlen((char *)stringBuf);
 148
 149                 while (*stringBuf)
 150                 {
 151                     sepBuf = (STRPTR)strstr((char *)stringBuf, (char *)SHArg(SEPARATOR));
 152                     if (sepBuf && (sepBuf == stringBuf))
 153                         wordCnt--;
 154
 155                     if (0 < wordCnt)
 156                         FPutC(Output(), *stringBuf++);
 157                     else
 158                         break;
 159                 }
 160             }
 161
 162             FreeVec(wordBounds);
 163             rc = RETURN_OK;
 164         }
 165     }
 166
 167     if (SHArg(CHAR))
 168     {
 169         if ((charBounds = getBoundaries(SHArg(CHAR), DOSBase, SysBase)) != NULL)
 170         {
 171             if (0 != charBounds->Start)
 172                 stringBuf += charBounds->Start - 1;
 173
 174             while((stringBuf - SHArg(STRING)) < ((0 != charBounds->End) ? min(stringLen, charBounds->End) : stringLen))
 175             {
 176                 FPutC(Output(), *stringBuf++);
 177             }
 178
 179             FreeVec(charBounds);
 180             rc = RETURN_OK;
 181         }
 182     }
 183
 184     if (rc == RETURN_OK)
 185         FPutC(Output(), '\n');
 186     else
 187     {
 188         ioerr = IoErr();
 189         PrintFault(ioerr, (CONST_STRPTR)"Cut");
 190         if (ioerr == ERROR_BAD_TEMPLATE)
 191             rc = RETURN_ERROR;
 192     }
 193
 194     return rc;
 195
 196     AROS_SHCOMMAND_EXIT
 197 }
 198
 199
 200 static struct Bounds *getBoundaries(STRPTR String, APTR DOSBase, struct ExecBase *SysBase)
 201 {
 202     CONST_STRPTR buffer;
 203     struct Bounds *bounds;
 204
 205     if ((buffer = String) == NULL)
 206     {
 207         SetIoErr(ERROR_BAD_TEMPLATE);
 208         return NULL;
 209     }
 210
 211     D(bug("[Cut] getBoundaries() buffer = '%s'\n", buffer));
 212
 213     if ((bounds = AllocVec(sizeof(struct Bounds), MEMF_ANY | MEMF_CLEAR)) != NULL)
 214     {
 215         if (*buffer != '-')
 216         {
 217             buffer += StrToLong(buffer, &bounds->Start);
 218         }
 219
 220         /* It is mandatory that boundaries are separated by '-'! */
 221         if ((*buffer) && (*buffer++ == '-'))
 222         {
 223             if (*buffer)
 224             {
 225                 StrToLong(buffer, &bounds->End);
 226             }
 227         }
 228         else
 229             bounds->End = bounds->Start;
 230
 231         D(bug("[Cut] getBoundaries() bounds->Start = %ld, bounds->End = %ld\n",
 232             bounds->Start, bounds->End));
 233     }
 234
 235     return bounds;
 236 }
 237
 238