ls -lahtr | grep install.txt && echo “exit status $?”

-rw-r–r–. 1 root root  55K Jun  9 03:20 install.txt
-rw-r–r–. 1 root root  13K Jun  9 03:22 install.txt.gz
-rw-r–r–. 1 root root  13K Jun  9 03:27 install.txt2.gz
-rw-r–r–. 1 root root  15K Jun  9 03:42 install.txt3.gz

exit status 0

Exit status:
0  if OK,
1  if minor problems (e.g., cannot access subdirectory),
2  if serious trouble (e.g., cannot access command-line argument).

l: listing format
a : all
h: print sizes in human readable format
t: sort by modification time
r: reverse order while sorting