explainshell.com - cat %2Fhome%2Fmarcos%2FEvidencias%2FBulk_PC-20170427_%2Frfc822.txt %7C egrep %22%5Ba-zA-Z%5D*%5B%2C%5D %5B0-9%5D* %5Ba-zA-Z%5D* %5B0-9%5D* %5B0-9%5D*%5B%3A%5D%5B0-9%5D*%5B%3A%5D%5B0-9%5D*%22 %7C sort -k 5%2C5 %7C head

%2Fhome%2Fmarcos%2FEvidencias%2FBulk_PC-20170427_%2Frfc822.txt %7C egrep %22%5Ba-zA-Z%5D*%5B%2C%5D %5B0-9%5D* %5Ba-zA-Z%5D* %5B0-9%5D* %5B0-9%5D*%5B%3A%5D%5B0-9%5D*%5B%3A%5D%5B0-9%5D*%22 %7C sort -k 5%2C5 %7C head

concatenate files and print on the standard output

Concatenate FILE(s), or standard input, to standard output.

With no FILE, or when FILE is -, read standard input.

source manpages: cat