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Diff for /src/bin/expr/expr.1 between version 1.31.4.1 and 1.31.4.2

version 1.31.4.1, 2012/05/23 10:07:04 version 1.31.4.2, 2012/10/30 18:46:06
Line 145  an error occurred (such as memory alloca
Line 145  an error occurred (such as memory alloca
 .Sh EXAMPLES  .Sh EXAMPLES
 .Bl -enum  .Bl -enum
 .It  .It
 The following example adds one to the variable a.  The following example adds one to variable
   .Dq a :
 .Dl a=`expr $a + 1`  .Dl a=`expr $a + 1`
 .It  .It
 The following example returns zero, due to subtraction having higher precedence  The following example returns zero, due to subtraction having higher precedence
 than '\*[Am]' operator.  than the
   .Dq \*[Am]
   operator:
 .Dl expr 1 '\*[Am]' 1 - 1  .Dl expr 1 '\*[Am]' 1 - 1
 .It  .It
 The following example returns the filename portion of a pathname stored  The following example returns the filename portion of a pathname stored
 in variable a.  in variable
   .Dq a :
 .Dl expr "/$a" Li : '.*/\e(.*\e)'  .Dl expr "/$a" Li : '.*/\e(.*\e)'
 .It  .It
 The following example returns the number of characters in variable a.  The following example returns the number of characters in variable
   .Dq a :
 .Dl expr $a Li : '.*'  .Dl expr $a Li : '.*'
 .El  .El
 .Sh COMPATIBILITY  .Sh COMPATIBILITY
Line 164  This implementation of
Line 169  This implementation of
 .Nm  .Nm
 internally uses 64 bit representation of integers and checks for  internally uses 64 bit representation of integers and checks for
 over- and underflows.  over- and underflows.
 It also treats / (division mark) and  It also treats
 option '--' correctly depending upon context.  .Dq /
   (the division mark) and option
   .Dq --
   correctly depending upon context.
 .Pp  .Pp
 .Nm  .Nm
 on other systems (including  on other systems (including
Line 182  can only process values between -2147483
Line 190  can only process values between -2147483
 On other systems,  On other systems,
 .Nm  .Nm
 might also not work correctly for regular expressions where  might also not work correctly for regular expressions where
 either side contains single forward slash, like this:  either side contains
   .Dq /
   (a single forward slash), like this:
 .Bd -literal -offset indent  .Bd -literal -offset indent
 expr / : '.*/\e(.*\e)'  expr / : '.*/\e(.*\e)'
 .Ed  .Ed
 .Pp  .Pp
 If this is the case, you might use // (double forward slash)  If this is the case, you might use
   .Dq //
   (a double forward slash)
 to avoid confusion with the division operator:  to avoid confusion with the division operator:
 .Bd -literal -offset indent  .Bd -literal -offset indent
 expr "//$a" : '.*/\e(.*\e)'  expr "//$a" : '.*/\e(.*\e)'
Line 196  expr "//$a" : '.*/\e(.*\e)'
Line 208  expr "//$a" : '.*/\e(.*\e)'
 According to  According to
 .St -p1003.2 ,  .St -p1003.2 ,
 .Nm  .Nm
 has to recognize special option '--', treat it as an end of command  has to recognize special option
 line options and ignore it.  .Dq -- ,
   treat it as a delimiter to mark the end of command
   line options, and ignore it.
 Some  Some
 .Nm  .Nm
 implementations don't recognize it at all, others  implementations don't recognize it at all; others
 might ignore it even in cases where doing so results in syntax  might ignore it even in cases where doing so results in syntax
 error.  error.
 There should be same result for both following examples,  There should be same result for both following examples,
Line 215  Although
Line 229  Although
 .Nx  .Nx
 .Nm  .Nm
 handles both cases correctly, you should not depend on this behavior  handles both cases correctly, you should not depend on this behavior
 for portability reasons and avoid passing bare '--' as first  for portability reasons and avoid passing a bare
   .Dq --
   as the first
 argument.  argument.
 .Sh STANDARDS  .Sh STANDARDS
 The  The
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  Added in v.1.31.4.2
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