dcl-pr ShowMSG extpgm('QMHSNDPM');      
 *n char(7) const;                      
 *n char(20) const;                     
 *n char(32767) const options(*varsize);
 *n int(10) const;                      
 *n char(10) const;                     
 *n char(10) const;                     
 *n int(10) const;                      
 *n char(4);                            
 *n char(32767) options(*varsize);      
end-pr;                                 
                                        
                                        
dcl-ds ErrorCode;                 

wc -l filename.txt

or

cat -n filename.txt

QSH CMD('/QOpenSys/pkgs/bin/find /directory_where_files_are/ -mtime +10 -type f -name ''*.pdf'' -delete')