Apr 3, 2012 · The shell splits tokens based on the contents of the IFS environment variable. Its default value is \t\n; i.e., whitespace, tab, and newline. Expanding "$@" gives you a pristine …

The shell treats several parameters specially. These parameters may only be referenced; assignment to them is not allowed. [...]? Expands to the exit status of the most recently …

Feb 20, 2011 · This latter usage is faster, does not contaminate the shell's variable namespace with what amounts to temp variables, can often be a lot more readable for humans and …

The above (along with many more forms of ${parameter…something_else} constructs) are discussed at greater length in the shell’s man page, bash(1). A Note on Quotes. Note that you …

Shell - "Shell" is a program, which facilitates the interaction between the user and the operating system (kernel). There are many shell implementations available, like sh, Bash, C shell, Z …

In shell terminology, eval is a built-in, not a function. In practice, built-ins behave a lot like functions that don't have an in-language definition, but not quite (as becomes apparent if you …

You can always check the man page of your shell. man bash says: Special Parameters # Expands to the number of positional parameters in decimal. Therefore a shell script can check …

As an aside, all-caps variables are defined by POSIX for variable names with meaning to the operating system or shell itself, whereas names with at least one lowercase character are …

Sep 14, 2012 · $0 is the name of the shell or shell script. Most of the above can be found under Special Parameters in the Bash Reference Manual. Here are all the environment variables set …

The shell is the program which actually processes commands and returns output. Most shells also manage foreground and background processes, command history and command line editing. …