Tcl Requires Chilkat v11.1.0+

Regular Expression with Multiple Matches and Capture Groups

See more Regular Expressions Examples

Demonstrates a regular expression with multiple matches and capture groups for each match.

Note: Chilkat uses PCRE2. See PCRE2 Regular Expressions
Also see: PCRE2 Performance

Tcl

load ./chilkat.dll

set success 0

set pattern "Name:\\s+(\\w+)\\s+(\\w+),\\s+Email:\\s+(\\S+)"

set sb [new_CkStringBuilder]

set crlf 1
CkStringBuilder_AppendLine $sb "Name: John Smith, Email: john.smith@example.com" $crlf
CkStringBuilder_AppendLine $sb "Name: Jack Johnson, Email: jack.johnson@example.com" $crlf
CkStringBuilder_AppendLine $sb "Name: Mary Adams, Email: mary.adams@example.com" $crlf

puts [CkStringBuilder_getAsString $sb]

#  We have the following string:
#  Name: John Smith, Email: john.smith@example.com
#  Name: Jack Johnson, Email: jack.johnson@example.com
#  Name: Mary Adams, Email: mary.adams@example.com

set json [new_CkJsonObject]

CkJsonObject_put_EmitCompact $json 0

set timeoutMs 2000
set numMatches [CkStringBuilder_RegexMatch $sb $pattern $json $timeoutMs]
if {$numMatches < 0} then {
    #  Probably an error in the regular expression.
    #  Suggestion: Use AI to help create and/or diagnose regular expressions.
    puts [CkStringBuilder_lastErrorText $sb]
    delete_CkStringBuilder $sb
    delete_CkJsonObject $json
    exit
}

#  Examine the matches:
puts [CkJsonObject_emit $json]

#  This is the JSON with the match information.
#  See the JSON parsing code below to get the matched capture group values.

#  {
#    "match": [
#      {
#        "group": [
#          {
#            "cap": "Name: John Smith, Email: john.smith@example.com",
#            "idx": 0,
#            "len": 47
#          },
#          {
#            "cap": "John",
#            "idx": 6,
#            "len": 4
#          },
#          {
#            "cap": "Smith",
#            "idx": 11,
#            "len": 5
#          },
#          {
#            "cap": "john.smith@example.com",
#            "idx": 25,
#            "len": 22
#          }
#        ]
#      },
#      {
#        "group": [
#          {
#            "cap": "Name: Jack Johnson, Email: jack.johnson@example.com",
#            "idx": 49,
#            "len": 51
#          },
#          {
#            "cap": "Jack",
#            "idx": 55,
#            "len": 4
#          },
#          {
#            "cap": "Johnson",
#            "idx": 60,
#            "len": 7
#          },
#          {
#            "cap": "jack.johnson@example.com",
#            "idx": 76,
#            "len": 24
#          }
#        ]
#      },
#      {
#        "group": [
#          {
#            "cap": "Name: Mary Adams, Email: mary.adams@example.com",
#            "idx": 102,
#            "len": 47
#          },
#          {
#            "cap": "Mary",
#            "idx": 108,
#            "len": 4
#          },
#          {
#            "cap": "Adams",
#            "idx": 113,
#            "len": 5
#          },
#          {
#            "cap": "mary.adams@example.com",
#            "idx": 127,
#            "len": 22
#          }
#        ]
#      }
#    ]
#  }

#  Important:  Capture group 0 always contains the entire match — that is, the portion of the input string that matches the full regular expression.

set i 0
set matchCount [CkJsonObject_SizeOfArray $json "match"]
while {$i < $matchCount} {
    puts "Match [expr $i + 1]:"
    CkJsonObject_put_I $json $i
    set j 0
    set numCaptureGroups [CkJsonObject_SizeOfArray $json "match[i].group"]
    while {$j < $numCaptureGroups} {
        CkJsonObject_put_J $json $j
        set cap [CkJsonObject_stringOf $json "match[i].group[j].cap"]
        puts "$j: $cap"
        set j [expr $j + 1]
    }
    set i [expr $i + 1]
}

#  Capture group 0 always contains the entire match — that is, the portion of the input string that matches the full regular expression.

#  Output

#  Match 1:
#  0: Name: John Smith, Email: john.smith@example.com
#  1: John
#  2: Smith
#  3: john.smith@example.com
#  Match 2:
#  0: Name: Jack Johnson, Email: jack.johnson@example.com
#  1: Jack
#  2: Johnson
#  3: jack.johnson@example.com
#  Match 3:
#  0: Name: Mary Adams, Email: mary.adams@example.com
#  1: Mary
#  2: Adams
#  3: mary.adams@example.com

delete_CkStringBuilder $sb
delete_CkJsonObject $json