Matching at the beginning of a string

The unquoted caret ^ matches the string at the beginning of line. The ^ is only the anchor if it is the first character in the regular expression. For example, we use the /^J/ regular expression to match all the lines that begin with J. It will print the employee information of those whose first name begins with the J character in the employee database:

$ awk '/^J/{ print }' emp.dat

The output on execution of the preceding code is as follows:

Jack    Singh   9857532312  jack@gmail.com      M   hr      2000
Jane    Kaur    9837432312  jane@gmail.com      F   hr      1800
Julie   Kapur   8826234556  julie@yahoo.com     F   Ops     2500
John    Kapur   9911556789  john@gmail.com      M   hr      2200

We can also use the anchor, ^ (caret), with the string match operator (~) to match the field beginning with a specified character. In the following example, we print all the lines whose second field begins with S. It will print employee information for those employees whose last name begins with the S character, as follows:

$ awk '$2 ~ /^S/{ print }' emp.dat

The output on execution of the preceding code is as follows:

Jack    Singh   9857532312  jack@gmail.com      M   hr      2000
Amit    Sharma  9911887766  amit@yahoo.com      M   lgs     2350
Hari    Singh   8827255666  hari@yahoo.com      M   Ops     2350
Victor  Sharma  8826567898  vics@hotmail.com    M   Ops     2500
Ginny   Singh   9857123466  ginny@yahoo.com     F   hr      2250
Amy     Sharma  9857536898  amys@hotmail.com    F   Ops     2500
Vina    Singh   8811776612  vina@yahoo.com      F   lgs     2300