bash - letters "A,a" of ouput of commands executed within backstick are being replacing with empty space, Why? - Ask Ubuntu

here snapshot of shell missing "a" characters in it!! i'm running ubuntu 16.04

this happen if ifs variable got a in it.  try following commands:

$ echo "$ifs"   # note: quotes important.                 # guess output “a”, or contains “a”. $ pwd           # expect work.  $ echo "`pwd`"  # again, quotes important.                 # expect give correct output.

ifs shell’s list of internal field separators.  character appears in $ifs treated if space when doing word splitting of unquoted parameter expansions , command substitution.

there’s no reason ifs variable have gotten a in it; i.e., if that’s happened, have no idea why happened.  if start new command window (i.e., xterm or whatever use) , problem goes away, probably localized current command window, , probably not come back.  but, if new command window has same problem, should search ~/.* files (i.e., ~/.bashrc, ~/.bash_profile, ~/.profile, etc.) command says ifs=something.