msgappread

This reads the next message from fileId, an open file handle, and appends the data to msgId.

msgappread ?-stats statsVar? len10 msgId fileId
msgappread ?-stats statsVar? nl msgId fileId
msgappread ?-stats statsVar? raw msgId fileId len

If you specify a len10 or nl read, then use the appropriate message boundary to terminate the read. Supply a read length, len, for raw reads.

If you supply a statsVar variable name, then the variable is set to contain a list of two values:

  • todo done

    todo is the number of bytes requested. This is the length implied by a len10 record header, 0 for nl reads, or the len value for raw reads.

    done is the actual number of characters read. These values are useful when a read fails.

This command returns the number of bytes read.