Linux Redirection and Pipes
# output redirection
cat 123.txt > onetwothree.txt redirects output to a file — default nature is to clobber the target file and populate it from the input stream # append redirection
cat 123.txt >> number.txt creates number.txt if it does not exist, or appends if it does cat 456.txt >> number.txt appends more content to the same file # pipes
Pipes connect the output stream of one command to the input stream of a subsequent command.
cat 123.txt | sort sort the contents of a file cat 456.txt 123.txt | sort concatenate two files, then sort cat 456.txt 123.txt | sort | grep 3 chain multiple pipes: concatenate, sort, then filter