I am running a file via batch file
Batch File:
sqlplus admin/admin@SERVER @abc.sql > output.txt
SQL File abc.sql:
s
-S
seems to be what you're looking for;
sqlplus -S admin/admin@SERVER @abc.sql > output.txt
-S[ILENT]
Suppresses all SQL*Plus information and prompt messages, including the command prompt, the echoing of commands, and the banner normally displayed when you start SQL*Plus. If you omit username or password, SQL*Plus prompts for them, but the prompts are not visible. Use SILENT to invoke SQL*Plus within another program so that the use of SQL*Plus is invisible to the user.