I have a file like this with tab separated two columns: ENSG00000242268.2    0.07563 ENSG00000270112.3    0.09976 ENSG00000167578.15   4.38608 ENSG00000273842.1    0.0 ENSG00000078237.5    4.08856I would like to remove the numeric extensions from the end in the 1st column, so the output will be: ENSG00000242268    0.07563 ENSG00000270112    0.09976 ENSG00000167578    4.38608 ENSG00000273842    0.0 ENSG00000078237    4.08856Simply doing sed 's/\..*$//' returns only first column value and using awk with field separator '.' , awk -F'.' removes the values from second column too as there are decimal numbers.A similar question has been answered here:removing extensions in a columnI am still not being able to delete just from column 1st only. 
Deleting extension only from the first column
awk;sed;cut
awk solution:awk -F'\t' '{sub(/\..+$/,,$1)}1' OFS='\t' file-F'\t' - field separatorsub(/\..+$/,,$1) - removes . with following chars from the 1st field at onceThe output:ENSG00000242268 0.07563ENSG00000270112 0.09976ENSG00000167578 4.38608ENSG00000273842 0.0ENSG00000078237 4.08856Or with simple sed approach:sed 's/\.[0-9]*//' file