Use Show Performance Statistics option, while running your job.
This will give you records read from source, written to output link and written to Reject link.
If you want job statistics in a file, Call the DSendJobReport with the argument 2;directorypath in the "After routine" of the job for which the statistics are required. This creates the job log in text format in the directorypath specified.
This will give you number of records read, written and rejected. You could write a shell script to format it if required.