i have 4 files which are like        file A       >TCONS_00000867       >TCONS_00001442       >TCONS_00001447       >TCONS_00001528       >TCONS_00001529       >TCONS_00001668       >TCONS_00001921       file b       >TCONS_00001528       >TCONS_00001529       >TCONS_00001668       >TCONS_00001921       >TCONS_00001922       >TCONS_00001924       file c       >TCONS_00001529       >TCONS_00001668       >TCONS_00001921       >TCONS_00001922       >TCONS_00001924       >TCONS_00001956       >TCONS_00002048       file d       >TCONS_00001922       >TCONS_00001924       >TCONS_00001956       >TCONS_00002048all files contain more than 2000 lines and sorted for first column. i want to find common lines in all files. i tried awk and grep and comm but not working
find common lines between multiple files
text processing
Since the files are already sorted:comm -12 a b |  comm -12 - c |  comm -12 - d