This manual is the definitive reference for GNU Bash, the standard GNU command-line interpreter.
GNU Bash is a complete implementation of the POSIX.2 shell specification (/bin/sh), with additional features from the C-shell (csh) and Korn shell (ksh). Most Bourne shell scripts can be run by Bash without modification.
GNU Bash is free software, distributed under the terms of the GNU General Public License (GPL). It runs on GNU (GNU/Linux) and Unix systems. Versions are also available for Microsoft Windows. Это и многое другое вы найдете в книге GNU Bash Reference Manual (Chet Ramey, Brian Fox)