Article of the week: It’s Past Time To Stop Using egrep & fgrep Commands
The egrep and fgrep commands have been deprecated since 2007. Beginning with GNU Grep 3.8 today, calling these commands will now issue a warning to the user that instead they should use
grep -Eandgrep -F, respectively.
Tip of the week: Using brace expansion:
# Create some files
% for num in {1..4}; do echo "file no. ${num}" > "/tmp/file${num}"; done
# Select files to print
% cat /tmp/file{1,3}
file no. 1
file no. 3
# Select a range of files to print:
% cat /tmp/file{2..4}
file no. 2
file no. 3
file no. 4
# Make a copy of a file with a new extension:
% cp /tmp/file1{,.txt}
% ls -1 /tmp/
file1
file1.txt
file2
file3
file4
# Create multiple directories
% mkdir -p /tmp/{alpha,beta}/{one,two,three}
% tree -dL 2 /tmp
/tmp
├── alpha
│ ├── one
│ ├── three
│ └── two
└── beta
├── one
├── three
└── two