The row number is displayed when the file is viewed in linux.

Show the line number when viewing the file in linux [root @ 1-minetc] # cat-nrsyslog.conf // show all lines (including empty lines) [root @ 1-minetc] # cat-brsyslog.conf // display all row numbers (but not empty rows) or :... in linux, the row number [root @ 1-min etc] # cat-n rsyslog is displayed. conf // display all row numbers (including empty rows) [root @ 1-min etc] # cat-B rsyslog. conf // display all row numbers (but not empty rows) or [root @ 1-min etc] # nl-ba rsyslog. conf // display all row numbers (including empty rows) [root @ 1-min etc] # nl-bt rsyslog. conf // display all row numbers (but not empty rows) or [root @ 1-min etc] # less-N rsyslog. conf // show all row numbers (including empty rows) cat option:-n show row numbers (including empty rows)-B show row numbers (excluding empty rows) nl option: -row B can be displayed in either of the following ways: a indicates displaying all rows (including empty rows) and t indicates displaying all non-blank rows (excluding empty rows) that is,-ba // display all row numbers (including empty rows)-bt // display all row numbers (but not empty rows)