new StrLen and StrSub

Parser/Gmsh.l

@@ -275,6 +275,8 @@ StrRelative             return tStrRelative;
 StrFind                 return tStrFind;
 StrCmp                  return tStrCmp;
 StrChoice               return tStrChoice;
+StrLen                  return tStrLen;
+StrSub                  return tStrSub;
 Show                    return tShow;
 Symmetry                return tSymmetry;
 Slide                   return tSlide;

Parser/Gmsh.tab.hpp

@@ -84,148 +84,150 @@
      tStrReplace = 300,
      tAbsolutePath = 301,
      tDirName = 302,
-     tFind = 303,
-     tStrFind = 304,
-     tStrCmp = 305,
-     tStrChoice = 306,
-     tUpperCase = 307,
-     tLowerCase = 308,
-     tLowerCaseIn = 309,
-     tTextAttributes = 310,
-     tBoundingBox = 311,
-     tDraw = 312,
-     tSetChanged = 313,
-     tToday = 314,
-     tFixRelativePath = 315,
-     tCurrentDirectory = 316,
-     tSyncModel = 317,
-     tNewModel = 318,
-     tOnelabAction = 319,
-     tOnelabRun = 320,
-     tCpu = 321,
-     tMemory = 322,
-     tTotalMemory = 323,
-     tCreateTopology = 324,
-     tCreateTopologyNoHoles = 325,
-     tDistanceFunction = 326,
-     tDefineConstant = 327,
-     tUndefineConstant = 328,
-     tDefineNumber = 329,
-     tDefineString = 330,
-     tSetNumber = 331,
-     tSetString = 332,
-     tPoint = 333,
-     tCircle = 334,
-     tEllipse = 335,
-     tLine = 336,
-     tSphere = 337,
-     tPolarSphere = 338,
-     tSurface = 339,
-     tSpline = 340,
-     tVolume = 341,
-     tCharacteristic = 342,
-     tLength = 343,
-     tParametric = 344,
-     tElliptic = 345,
-     tRefineMesh = 346,
-     tAdaptMesh = 347,
-     tRelocateMesh = 348,
-     tPlane = 349,
-     tRuled = 350,
-     tTransfinite = 351,
-     tComplex = 352,
-     tPhysical = 353,
-     tCompound = 354,
-     tPeriodic = 355,
-     tUsing = 356,
-     tPlugin = 357,
-     tDegenerated = 358,
-     tRecursive = 359,
-     tRotate = 360,
-     tTranslate = 361,
-     tSymmetry = 362,
-     tDilate = 363,
-     tExtrude = 364,
-     tLevelset = 365,
-     tAffine = 366,
-     tRecombine = 367,
-     tSmoother = 368,
-     tSplit = 369,
-     tDelete = 370,
-     tCoherence = 371,
-     tIntersect = 372,
-     tMeshAlgorithm = 373,
-     tReverse = 374,
-     tLayers = 375,
-     tScaleLast = 376,
-     tHole = 377,
-     tAlias = 378,
-     tAliasWithOptions = 379,
-     tCopyOptions = 380,
-     tQuadTriAddVerts = 381,
-     tQuadTriNoNewVerts = 382,
-     tQuadTriSngl = 383,
-     tQuadTriDbl = 384,
-     tRecombLaterals = 385,
-     tTransfQuadTri = 386,
-     tText2D = 387,
-     tText3D = 388,
-     tInterpolationScheme = 389,
-     tTime = 390,
-     tCombine = 391,
-     tBSpline = 392,
-     tBezier = 393,
-     tNurbs = 394,
-     tNurbsOrder = 395,
-     tNurbsKnots = 396,
-     tColor = 397,
-     tColorTable = 398,
-     tFor = 399,
-     tIn = 400,
-     tEndFor = 401,
-     tIf = 402,
-     tElseIf = 403,
-     tElse = 404,
-     tEndIf = 405,
-     tExit = 406,
-     tAbort = 407,
-     tField = 408,
-     tReturn = 409,
-     tCall = 410,
-     tSlide = 411,
-     tMacro = 412,
-     tShow = 413,
-     tHide = 414,
-     tGetValue = 415,
-     tGetStringValue = 416,
-     tGetEnv = 417,
-     tGetString = 418,
-     tGetNumber = 419,
-     tHomology = 420,
-     tCohomology = 421,
-     tBetti = 422,
-     tExists = 423,
-     tFileExists = 424,
-     tGMSH_MAJOR_VERSION = 425,
-     tGMSH_MINOR_VERSION = 426,
-     tGMSH_PATCH_VERSION = 427,
-     tGmshExecutableName = 428,
-     tSetPartition = 429,
-     tNameToString = 430,
-     tStringToName = 431,
-     tAFFECTDIVIDE = 432,
-     tAFFECTTIMES = 433,
-     tAFFECTMINUS = 434,
-     tAFFECTPLUS = 435,
-     tOR = 436,
-     tAND = 437,
-     tNOTEQUAL = 438,
-     tEQUAL = 439,
-     tGREATEROREQUAL = 440,
-     tLESSOREQUAL = 441,
-     UNARYPREC = 442,
-     tMINUSMINUS = 443,
-     tPLUSPLUS = 444
+     tStrSub = 303,
+     tStrLen = 304,
+     tFind = 305,
+     tStrFind = 306,
+     tStrCmp = 307,
+     tStrChoice = 308,
+     tUpperCase = 309,
+     tLowerCase = 310,
+     tLowerCaseIn = 311,
+     tTextAttributes = 312,
+     tBoundingBox = 313,
+     tDraw = 314,
+     tSetChanged = 315,
+     tToday = 316,
+     tFixRelativePath = 317,
+     tCurrentDirectory = 318,
+     tSyncModel = 319,
+     tNewModel = 320,
+     tOnelabAction = 321,
+     tOnelabRun = 322,
+     tCpu = 323,
+     tMemory = 324,
+     tTotalMemory = 325,
+     tCreateTopology = 326,
+     tCreateTopologyNoHoles = 327,
+     tDistanceFunction = 328,
+     tDefineConstant = 329,
+     tUndefineConstant = 330,
+     tDefineNumber = 331,
+     tDefineString = 332,
+     tSetNumber = 333,
+     tSetString = 334,
+     tPoint = 335,
+     tCircle = 336,
+     tEllipse = 337,
+     tLine = 338,
+     tSphere = 339,
+     tPolarSphere = 340,
+     tSurface = 341,
+     tSpline = 342,
+     tVolume = 343,
+     tCharacteristic = 344,
+     tLength = 345,
+     tParametric = 346,
+     tElliptic = 347,
+     tRefineMesh = 348,
+     tAdaptMesh = 349,
+     tRelocateMesh = 350,
+     tPlane = 351,
+     tRuled = 352,
+     tTransfinite = 353,
+     tComplex = 354,
+     tPhysical = 355,
+     tCompound = 356,
+     tPeriodic = 357,
+     tUsing = 358,
+     tPlugin = 359,
+     tDegenerated = 360,
+     tRecursive = 361,
+     tRotate = 362,
+     tTranslate = 363,
+     tSymmetry = 364,
+     tDilate = 365,
+     tExtrude = 366,
+     tLevelset = 367,
+     tAffine = 368,
+     tRecombine = 369,
+     tSmoother = 370,
+     tSplit = 371,
+     tDelete = 372,
+     tCoherence = 373,
+     tIntersect = 374,
+     tMeshAlgorithm = 375,
+     tReverse = 376,
+     tLayers = 377,
+     tScaleLast = 378,
+     tHole = 379,
+     tAlias = 380,
+     tAliasWithOptions = 381,
+     tCopyOptions = 382,
+     tQuadTriAddVerts = 383,
+     tQuadTriNoNewVerts = 384,
+     tQuadTriSngl = 385,
+     tQuadTriDbl = 386,
+     tRecombLaterals = 387,
+     tTransfQuadTri = 388,
+     tText2D = 389,
+     tText3D = 390,
+     tInterpolationScheme = 391,
+     tTime = 392,
+     tCombine = 393,
+     tBSpline = 394,
+     tBezier = 395,
+     tNurbs = 396,
+     tNurbsOrder = 397,
+     tNurbsKnots = 398,
+     tColor = 399,
+     tColorTable = 400,
+     tFor = 401,
+     tIn = 402,
+     tEndFor = 403,
+     tIf = 404,
+     tElseIf = 405,
+     tElse = 406,
+     tEndIf = 407,
+     tExit = 408,
+     tAbort = 409,
+     tField = 410,
+     tReturn = 411,
+     tCall = 412,
+     tSlide = 413,
+     tMacro = 414,
+     tShow = 415,
+     tHide = 416,
+     tGetValue = 417,
+     tGetStringValue = 418,
+     tGetEnv = 419,
+     tGetString = 420,
+     tGetNumber = 421,
+     tHomology = 422,
+     tCohomology = 423,
+     tBetti = 424,
+     tExists = 425,
+     tFileExists = 426,
+     tGMSH_MAJOR_VERSION = 427,
+     tGMSH_MINOR_VERSION = 428,
+     tGMSH_PATCH_VERSION = 429,
+     tGmshExecutableName = 430,
+     tSetPartition = 431,
+     tNameToString = 432,
+     tStringToName = 433,
+     tAFFECTDIVIDE = 434,
+     tAFFECTTIMES = 435,
+     tAFFECTMINUS = 436,
+     tAFFECTPLUS = 437,
+     tOR = 438,
+     tAND = 439,
+     tNOTEQUAL = 440,
+     tEQUAL = 441,
+     tGREATEROREQUAL = 442,
+     tLESSOREQUAL = 443,
+     UNARYPREC = 444,
+     tMINUSMINUS = 445,
+     tPLUSPLUS = 446
    };
 #endif
 /* Tokens.  */
@@ -274,148 +276,150 @@
 #define tStrReplace 300
 #define tAbsolutePath 301
 #define tDirName 302
-#define tFind 303
-#define tStrFind 304
-#define tStrCmp 305
-#define tStrChoice 306
-#define tUpperCase 307
-#define tLowerCase 308
-#define tLowerCaseIn 309
-#define tTextAttributes 310
-#define tBoundingBox 311
-#define tDraw 312
-#define tSetChanged 313
-#define tToday 314
-#define tFixRelativePath 315
-#define tCurrentDirectory 316
-#define tSyncModel 317
-#define tNewModel 318
-#define tOnelabAction 319
-#define tOnelabRun 320
-#define tCpu 321
-#define tMemory 322
-#define tTotalMemory 323
-#define tCreateTopology 324
-#define tCreateTopologyNoHoles 325
-#define tDistanceFunction 326
-#define tDefineConstant 327
-#define tUndefineConstant 328
-#define tDefineNumber 329
-#define tDefineString 330
-#define tSetNumber 331
-#define tSetString 332
-#define tPoint 333
-#define tCircle 334
-#define tEllipse 335
-#define tLine 336
-#define tSphere 337
-#define tPolarSphere 338
-#define tSurface 339
-#define tSpline 340
-#define tVolume 341
-#define tCharacteristic 342
-#define tLength 343
-#define tParametric 344
-#define tElliptic 345
-#define tRefineMesh 346
-#define tAdaptMesh 347
-#define tRelocateMesh 348
-#define tPlane 349
-#define tRuled 350
-#define tTransfinite 351
-#define tComplex 352
-#define tPhysical 353
-#define tCompound 354
-#define tPeriodic 355
-#define tUsing 356
-#define tPlugin 357
-#define tDegenerated 358
-#define tRecursive 359
-#define tRotate 360
-#define tTranslate 361
-#define tSymmetry 362
-#define tDilate 363
-#define tExtrude 364
-#define tLevelset 365
-#define tAffine 366
-#define tRecombine 367
-#define tSmoother 368
-#define tSplit 369
-#define tDelete 370
-#define tCoherence 371
-#define tIntersect 372
-#define tMeshAlgorithm 373
-#define tReverse 374
-#define tLayers 375
-#define tScaleLast 376
-#define tHole 377
-#define tAlias 378
-#define tAliasWithOptions 379
-#define tCopyOptions 380
-#define tQuadTriAddVerts 381
-#define tQuadTriNoNewVerts 382
-#define tQuadTriSngl 383
-#define tQuadTriDbl 384
-#define tRecombLaterals 385
-#define tTransfQuadTri 386
-#define tText2D 387
-#define tText3D 388
-#define tInterpolationScheme 389
-#define tTime 390
-#define tCombine 391
-#define tBSpline 392
-#define tBezier 393
-#define tNurbs 394
-#define tNurbsOrder 395
-#define tNurbsKnots 396
-#define tColor 397
-#define tColorTable 398
-#define tFor 399
-#define tIn 400
-#define tEndFor 401
-#define tIf 402
-#define tElseIf 403
-#define tElse 404
-#define tEndIf 405
-#define tExit 406
-#define tAbort 407
-#define tField 408
-#define tReturn 409
-#define tCall 410
-#define tSlide 411
-#define tMacro 412
-#define tShow 413
-#define tHide 414
-#define tGetValue 415
-#define tGetStringValue 416
-#define tGetEnv 417
-#define tGetString 418
-#define tGetNumber 419
-#define tHomology 420
-#define tCohomology 421
-#define tBetti 422
-#define tExists 423
-#define tFileExists 424
-#define tGMSH_MAJOR_VERSION 425
-#define tGMSH_MINOR_VERSION 426
-#define tGMSH_PATCH_VERSION 427
-#define tGmshExecutableName 428
-#define tSetPartition 429
-#define tNameToString 430
-#define tStringToName 431
-#define tAFFECTDIVIDE 432
-#define tAFFECTTIMES 433
-#define tAFFECTMINUS 434
-#define tAFFECTPLUS 435
-#define tOR 436
-#define tAND 437
-#define tNOTEQUAL 438
-#define tEQUAL 439
-#define tGREATEROREQUAL 440
-#define tLESSOREQUAL 441
-#define UNARYPREC 442
-#define tMINUSMINUS 443
-#define tPLUSPLUS 444
+#define tStrSub 303
+#define tStrLen 304
+#define tFind 305
+#define tStrFind 306
+#define tStrCmp 307
+#define tStrChoice 308
+#define tUpperCase 309
+#define tLowerCase 310
+#define tLowerCaseIn 311
+#define tTextAttributes 312
+#define tBoundingBox 313
+#define tDraw 314
+#define tSetChanged 315
+#define tToday 316
+#define tFixRelativePath 317
+#define tCurrentDirectory 318
+#define tSyncModel 319
+#define tNewModel 320
+#define tOnelabAction 321
+#define tOnelabRun 322
+#define tCpu 323
+#define tMemory 324
+#define tTotalMemory 325
+#define tCreateTopology 326
+#define tCreateTopologyNoHoles 327
+#define tDistanceFunction 328
+#define tDefineConstant 329
+#define tUndefineConstant 330
+#define tDefineNumber 331
+#define tDefineString 332
+#define tSetNumber 333
+#define tSetString 334
+#define tPoint 335
+#define tCircle 336
+#define tEllipse 337
+#define tLine 338
+#define tSphere 339
+#define tPolarSphere 340
+#define tSurface 341
+#define tSpline 342
+#define tVolume 343
+#define tCharacteristic 344
+#define tLength 345
+#define tParametric 346
+#define tElliptic 347
+#define tRefineMesh 348
+#define tAdaptMesh 349
+#define tRelocateMesh 350
+#define tPlane 351
+#define tRuled 352
+#define tTransfinite 353
+#define tComplex 354
+#define tPhysical 355
+#define tCompound 356
+#define tPeriodic 357
+#define tUsing 358
+#define tPlugin 359
+#define tDegenerated 360
+#define tRecursive 361
+#define tRotate 362
+#define tTranslate 363
+#define tSymmetry 364
+#define tDilate 365
+#define tExtrude 366
+#define tLevelset 367
+#define tAffine 368
+#define tRecombine 369
+#define tSmoother 370
+#define tSplit 371
+#define tDelete 372
+#define tCoherence 373
+#define tIntersect 374
+#define tMeshAlgorithm 375
+#define tReverse 376
+#define tLayers 377
+#define tScaleLast 378
+#define tHole 379
+#define tAlias 380
+#define tAliasWithOptions 381
+#define tCopyOptions 382
+#define tQuadTriAddVerts 383
+#define tQuadTriNoNewVerts 384
+#define tQuadTriSngl 385
+#define tQuadTriDbl 386
+#define tRecombLaterals 387
+#define tTransfQuadTri 388
+#define tText2D 389
+#define tText3D 390
+#define tInterpolationScheme 391
+#define tTime 392
+#define tCombine 393
+#define tBSpline 394
+#define tBezier 395
+#define tNurbs 396
+#define tNurbsOrder 397
+#define tNurbsKnots 398
+#define tColor 399
+#define tColorTable 400
+#define tFor 401
+#define tIn 402
+#define tEndFor 403
+#define tIf 404
+#define tElseIf 405
+#define tElse 406
+#define tEndIf 407
+#define tExit 408
+#define tAbort 409
+#define tField 410
+#define tReturn 411
+#define tCall 412
+#define tSlide 413
+#define tMacro 414
+#define tShow 415
+#define tHide 416
+#define tGetValue 417
+#define tGetStringValue 418
+#define tGetEnv 419
+#define tGetString 420
+#define tGetNumber 421
+#define tHomology 422
+#define tCohomology 423
+#define tBetti 424
+#define tExists 425
+#define tFileExists 426
+#define tGMSH_MAJOR_VERSION 427
+#define tGMSH_MINOR_VERSION 428
+#define tGMSH_PATCH_VERSION 429
+#define tGmshExecutableName 430
+#define tSetPartition 431
+#define tNameToString 432
+#define tStringToName 433
+#define tAFFECTDIVIDE 434
+#define tAFFECTTIMES 435
+#define tAFFECTMINUS 436
+#define tAFFECTPLUS 437
+#define tOR 438
+#define tAND 439
+#define tNOTEQUAL 440
+#define tEQUAL 441
+#define tGREATEROREQUAL 442
+#define tLESSOREQUAL 443
+#define UNARYPREC 444
+#define tMINUSMINUS 445
+#define tPLUSPLUS 446
 
 
 
@@ -433,7 +437,7 @@ typedef union YYSTYPE
   List_T *l;
 }
 /* Line 1529 of yacc.c.  */
-#line 437 "Gmsh.tab.hpp"
+#line 441 "Gmsh.tab.hpp"
 	YYSTYPE;
 # define yystype YYSTYPE /* obsolescent; will be withdrawn */
 # define YYSTYPE_IS_DECLARED 1

Parser/Gmsh.y

@@ -57,7 +57,7 @@
 #include "gmshPopplerWrapper.h"
 #endif
 
-  
+
   // Global parser variables
 std::string gmsh_yyname;
 int gmsh_yyerrorstate = 0;
@@ -130,7 +130,7 @@ struct doubleXstring{
 %token tAtan tAtan2 tSinh tCosh tTanh tFabs tFloor tCeil tRound
 %token tFmod tModulo tHypot tList
 %token tPrintf tError tStr tSprintf tStrCat tStrPrefix tStrRelative tStrReplace
-%token tAbsolutePath tDirName
+%token tAbsolutePath tDirName tStrSub tStrLen
 %token tFind tStrFind tStrCmp tStrChoice tUpperCase tLowerCase tLowerCaseIn
 %token tTextAttributes
 %token tBoundingBox tDraw tSetChanged tToday tFixRelativePath tCurrentDirectory
@@ -3437,7 +3437,7 @@ Command :
     }
 ;
 
-// S L I D E 
+// S L I D E
 
 Slide :
      tSlide '(' '{' RecursiveListOfDouble '}' ',' StringExpr ',' StringExpr ')'  tEND
@@ -3450,9 +3450,9 @@ Slide :
 	 is.push_back ((int) d);
        }
        gmshPopplerWrapper::instance()->setMacroForPages(is, $7, $9 );
-#endif       
+#endif
      }
-     
+
 // L O O P
 
 Loop :
@@ -5438,7 +5438,7 @@ FExpr_Single :
       $$ = matches;
       Free($3); Free($5);
     }
-  | tStrFind '(' StringExprVar ',' StringExprVar ')'
+  | tStrFind LP StringExprVar ',' StringExprVar RP
     {
       std::string s($3), substr($5);
       if(s.find(substr) != std::string::npos)
@@ -5447,7 +5447,12 @@ FExpr_Single :
         $$ = 0.;
       Free($3); Free($5);
     }
-  | tStrCmp '(' StringExprVar ',' StringExprVar ')'
+  | tStrLen LP StringExprVar RP
+    {
+      $$ = strlen($3);
+      Free($3);
+    }
+  | tStrCmp LP StringExprVar ',' StringExprVar RP
     {
       $$ = strcmp($3, $5);
       Free($3); Free($5);
@@ -6309,7 +6314,7 @@ StringExpr :
       }
       $$ = $3;
     }
-  | tStrChoice LP FExpr ',' StringExpr ',' StringExpr RP
+  | tStrChoice LP FExpr ',' StringExprVar ',' StringExprVar RP
     {
       if($3){
         $$ = $5;
@@ -6320,6 +6325,22 @@ StringExpr :
         Free($5);
       }
     }
+  | tStrSub LP StringExprVar ',' FExpr ',' FExpr RP
+    {
+      std::string in = $3;
+      std::string out = in.substr((int)$5, (int)$7);
+      $$ = (char *)Malloc((out.size() + 1) * sizeof(char));
+      strcpy($$, out.c_str());
+      Free($3);
+    }
+  | tStrSub LP StringExprVar ',' FExpr RP
+    {
+      std::string in = $3;
+      std::string out = in.substr((int)$5, std::string::npos);
+      $$ = (char *)Malloc((out.size() + 1) * sizeof(char));
+      strcpy($$, out.c_str());
+      Free($3);
+    }
   | tSprintf LP StringExprVar RP
     {
       $$ = $3;

doc/texinfo/gmsh.texi

@@ -1004,6 +1004,7 @@ parsing of the script file:
   Find(@var{expression-list-item}, @var{expression-list-item}) |
   StrFind(@var{char-expression}, @var{char-expression}) |
   StrCmp(@var{char-expression}, @var{char-expression}) |
+  StrLen(@var{char-expression}) |
   TextAttributes(@var{char-expression}<,@var{char-expression}@dots{}>) |
   Exists(@var{string}) | Exists(@var{string}~@{ @var{expression} @}) |
   FileExists(@var{char-expression}) |
@@ -1045,7 +1046,8 @@ first expression in the second (both of which can be lists).
 occurrence of the second @var{char-expression}. @code{StrCmp} compares
 the two strings (returns an integer greater than, equal to, or less than
 0, according as the first string is greater than, equal to, or less than
-the second string).  @code{TextAttributes} creates attributes for text
+the second string). @code{StrCmp} returns the length of the
+string. @code{TextAttributes} creates attributes for text
 strings. @code{Exists} checks if a variable with the given name exists
 (i.e., has been defined previously), and @code{FileExists} checks if the
 file with the given name exists.  @code{StringToName} creates a name
@@ -1145,7 +1147,9 @@ Character expressions are defined as:
   StrRelative ( @var{char-expression} ) |
   StrCat ( @var{char-expression} <,@dots{}> ) |
   Str ( @var{char-expression} <,@dots{}> ) |
-  StrChoice ( @var{expression}, @var{char-expression}, @var{char-expression}) |
+  StrChoice ( @var{expression}, @var{char-expression}, @var{char-expression} ) |
+  StrSub( @var{char-expression}, @var{expression}, @var{expression} ) |
+  StrSub( @var{char-expression}, @var{expression} ) |
   UpperCase ( @var{char-expression} ) |
   AbsolutePath ( @var{char-expression} ) |
   DirName ( @var{char-expression} ) |
@@ -1170,12 +1174,17 @@ extension) or the relative path of a file name. @code{StrCat} and
 @code{Str} permit to concatenate character expressions (@code{Str} adds
 a newline character after each string except the last).
 @code{StrChoice} returns the first or second @var{char-expression}
-depending on the value of @var{expression}. @code{UpperCase} converts
-the @var{char-expression} to upper case. @code{AbsolutePath} returns the
-absolute path of a file. @code{DirName} returns the directory of a file.
-@code{Sprintf} is equivalent to the @code{sprintf} C function (where
-@var{char-expression} is a format string that can contain floating point
-formatting characters: @code{%e}, @code{%g}, etc.) The various
+depending on the value of @var{expression}.  @code{StrSub} returns the
+portion of the string that starts at the character position given by the
+first @var{expression} and spans the number of characters given by the
+second @var{expression} or until the end of the string (whichever comes
+first; or always if the second @var{expression} is not
+provided). @code{UpperCase} converts the @var{char-expression} to upper
+case. @code{AbsolutePath} returns the absolute path of a
+file. @code{DirName} returns the directory of a file.  @code{Sprintf} is
+equivalent to the @code{sprintf} C function (where @var{char-expression}
+is a format string that can contain floating point formatting
+characters: @code{%e}, @code{%g}, etc.) The various
 @w{@var{char-option}s} are listed in @ref{Options}. @code{GetEnvThe}
 gets the value of an environment variable from the operating
 system. @code{GetString} allows to get a ONELAB string value (the second