Modifying message data

You can modify message data by adding data to a message or using the null option:

  • Adding data to a message with msginsert:

    msginsert adds a string to the message. An insertion offset can be specified. If it is not, then it defaults to 0, and the data are prepended to the message.

    For example:

    Input: msginsert message6 "This message contains "
    Output: 
    
    Input: msgget message6
    Output: This message contains some protocol reply data
    
    Input: msginsert message6 "more " 27
    Output:
    
    Input: msgget message6
    Output: This message contains some more protocol reply dat
  • Null option:

    msginsert's -cvtnull option is the opposite of msgget's. Use it to specify which character to convert to null as the string is added to the message.

    For example:

    Input: msgcreate -class protocol -recover -type reply
    Output: message4
    
    Input: msginsert -cvtnull X message4 "this data has an X\ embedded NULL"
    Output:
    
    Input: msgget message4
    Output: this data has an Ç embedded NULL
    
    Input: msgget -cvtnull Z message4
    Output: this data has an Z embedded NULL

    This command returns an empty string.