Filtering and Splitting Lines With AWK & "while read"

In this example lines contained in a ksh/bash String are:

• filtered (by awk)
• duplicate consecutive lines are removed (by awk)
• then split only using the shell internal "while read" feature (without needing to use "cut, awk"  or other external "binaries")

Example: if ${RESULT_STR} (see below) contains:

*********************** Backup Status of DB_29384_SITE1 ************************

Backup Type   Status                   Start Time       Error Message

------------- ------------------------ ---------------- ---------------------------

ARCHIVELOG    COMPLETED                2018.02.07 16:54 

ARCHIVELOG    COMPLETED WITH WARNINGS  2018.02.07 17:00 RMAN-08137: WARNING: ...

ARCHIVELOG    COMPLETED                2018.02.07 20:55 

ARCHIVELOG    COMPLETED WITH WARNINGS  2018.02.07 21:06 RMAN-08137: WARNING: ...

DB INCR       COMPLETED                2018.02.08 02:00  ARCHIVELOG    COMPLETED                2018.02.08 03:04 

DB INCR       COMPLETED                2018.02.08 03:06 

ARCHIVELOG    COMPLETED WITH WARNINGS  2018.02.08 03:53 RMAN-08137: WARNING: ...

ARCHIVELOG    COMPLETED                2018.02.08 04:54 

AWK: Filtering & Removing Duplicate Lines

The result of

print - "${RESULT_STR}" | 

  awk '/ RMAN-| ORA-/{ 

    MSG=substr($0, 86)

    if(MSG!=PREV){ 

      print MSG

      PREV=MSG 

    }

  }' 

is:

("/ RMAN-| ORA-/" filters the "interesting" lines – containing error/warning messages. "substr($0, 86)" returns the end of the string starting with column 57. "MSG and PREV" are used in order to remove duplicate consecutive lines)

RMAN-08137: WARNING: archived log not deleted, needed for standby or upstream capture process 

While Read: Splitting The Input

"errNr" gets the characters up to the first space, "errTxt" receives all other characters until the end of line

print - "${RESULT_STR}" | 

  awk '/ RMAN-| ORA-/{

    MSG=substr($0, 57)

    if(MSG!=PREV){ 

      print MSG

       PREV=MSG

   }

  }' |

  while read errNr errTxt ; do

    print - "errNr: ${errNr} / errTxt: ${errTxt} "

  done

Output

errNr: RMAN-08137: / errTxt: WARNING: archived log not deleted, needed for standby or upstream capture process 

Specifying a "while read" Delimiter

The delimiter can be changed from space to colon by using "IFS=':'"

IFS=':'

print - "${RESULT_STR}" |

  awk '/ RMAN-| ORA-/{MSG=substr($0, 57); if(MSG!=PREV){ print MSG; PREV=MSG }}' |

  while read errNr errTxt ; do

    print - "errNr: ${errNr} / errTxt: ${errTxt} "

  done

Output (without ':' after RMAN-08137)

errNr: RMAN-08137 / errTxt: WARNING: archived log not deleted, needed for standby or upstream capture process

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