diff options
| author | jtc <jtc@NetBSD.org> | 1993-10-04 22:06:59 +0000 |
|---|---|---|
| committer | jtc <jtc@NetBSD.org> | 1993-10-04 22:06:59 +0000 |
| commit | 441c51a9d552fbe50a4a8b34864324f978e8a462 (patch) | |
| tree | 09d529f339f0cb6da647ef661cdd778fd943ba40 /bin/expr/expr.1 | |
| parent | d143e6f1752187377d29ea4d5187b09a1e875640 (diff) | |
Document the new, less restrictive, behavior of the matching operator.
Diffstat (limited to 'bin/expr/expr.1')
| -rw-r--r-- | bin/expr/expr.1 | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/bin/expr/expr.1 b/bin/expr/expr.1 index 8b6cfeed778..a592564f8dd 100644 --- a/bin/expr/expr.1 +++ b/bin/expr/expr.1 @@ -28,7 +28,7 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.\" $Id: expr.1,v 1.4 1993/08/28 04:21:00 jtc Exp $ +.\" $Id: expr.1,v 1.5 1993/10/04 22:06:59 jtc Exp $ .\" .Dd July 3, 1993 .Dt EXPR 1 @@ -83,19 +83,19 @@ operator matches against .Ar expr2 , which must be a regular expression. The regular expression is anchored -to the begining of the string with an invisible -.Dq ^ , -therefore -.Dq ^ -is not a special character. +to the begining of the string with an implicit +.Dq ^ . .Pp -If the pattern contains at lest one regular expression -subexpression +If the match succeeds and the pattern contains at least one regular +expression subexpression .Dq "\e(...\e)" , the string corresponding to .Dq "\e1" is returned; otherwise the matching operator returns the number of characters matched. +If the match fails and the pattern contains a regular expression subexpression +the null string is returned; +otherwise 0. .El .Pp Parentheses are used for grouping in the usual manner. @@ -117,7 +117,7 @@ The following example returns the number of characters in variable a. The .Nm expr utility exits with one of the following values: -.Bl -tag -width Ds +.Bl -tag -width Ds -compact .It 0 the expression is neither an empty string nor 0. .It 1 |
