
Shells
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Shell Programming
Last revision August 6, 2004 Expressions can be used in assigning values to new variables; as substitutions in command lines in the script; and in flow-of-control statements : if , foreach , while , and switch .Redirection is the transferring of standard output to some other destination, such as another program, a file or a printer, instead of the display monitor (which is its default destination). Standard output, sometimes abbreviated stdout , is the destination of the output from command line (i.e., all-text mode) programs in Unix-like operating systems.
All about pipes, by The Linux Information Project (LINFO)
Shell (computing)
C shell
Here document
A here document (also called a here-document , a heredoc , a hereis , a here-string or a here-script ) is a way of specifying a string literal in command line shells including Unix shells ( sh , csh , ksh , Bash and zsh ) and in programming or scripting languages such as Perl , PHP , Python , PowerShell and Ruby . It preserves the line breaks and other whitespace (including indentation) in the text. Some languages allow variable substitution and command substitution inside the string.CSH Scripting Basics
This is a collection of useful one-line csh-commands and short multi-line contructs, intended to give some practical hints to both novice and veteran csh and sh users.

