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Full Discussion: I need to understand the differences between the bash shell and the Bourne shell
Top Forums Shell Programming and Scripting I need to understand the differences between the bash shell and the Bourne shell Post 302368471 by pludi on Thursday 5th of November 2009 01:29:25 AM
Old 11-05-2009
Microsoft, since the early days of DOS, uses the two bytes carriage-return/linefeed as end-of-line terminators (and ^Z instead of ^D for EOF). So this isn't a Windows 7 specialty. But when copy-and-pasting lines, the command prompt isn't sent that 2 byte sequence, but an emulation of the enter key, where it's up to the program to handle that correctly. Cygwin comes with both vim and emacs (and a multitude of other editors) that let you save files in UNIX format.

You can leave out the shebang line if you really only use the bash shell. But expect your script to fail as soon as someone tries to run it in another shell (ksh/csh/ash/dash/...). By default, the script is executed using the same shell the user is currently running, but with the shebang line you'll tell the system explicitly which shell to use. This is especially useful if you use different scripting languages:
  • You can write stand-alone awk programs using
    Code:
    #!/usr/bin/awk -f

  • Perl programs will almost guaranteed fail if you run them without stating the interpreter somewhere
The same is true for expect, TCL, Python, Ruby, ....

The standard output for bash (just like any other POSIX shell) is stdout. If that is connected to a terminal, output goes there. If it's connected to a file, likewise. Maybe it's just that your awk statement didn't match, and so didn't print anything.
 

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LEARN ABOUT DEBIAN

surfraw-update-path

SURFRAW-UPDATE-PATH(1)					User Contributed Perl Documentation				    SURFRAW-UPDATE-PATH(1)

NAME

       surfraw-update-path - updates PATH in shell config files

SYNOPSIS

       surfraw-update-path [-add] [-remove] [-check] [-sys] [-all] [-help] [-shell=SHELL]

DESCRIPTION

       surfraw-update-path adds the surfraw elvi directory (/usr/lib/surfraw) to your PATH in your shell's config file.

       Currently it supports bash, sh, csh, tcsh, ash, dash, ksh, pdksh, zsh, rc, and es

       Don't forget to login again or source your login files for it to take effect.

OPTIONS

       -check
	   Checks to see if the surfraw config code is present.  This is the default.

       -add
	   Adds the surfraw config code.

       -remove
	   Removes the surfraw config code

       -sys
	   Updates the system-wide shell config instead of the user.  Must be done as root.

       -shell=SHELL
	   Selects the shell to configure. Defaults to the value of the $SHELL environment variable.

	   Currently supported shells are:

	   sh, ash, bash, dash, csh, tcsh, ksh, pdksh, zsh, rc, and es.

       -all
	   Attempts to configure the startup files for all known shells

       -help
	   Gives a usage message

RETURN VALUE

       -check returns 0 if the surfraw code is present in the file, 1 if it is not found, or 2 on error.

       All other options return 0 on success, or 2 on error.

ENVIRONMENT

       SHELL
	   Used to determine which shell to configure, if -shell is not given.

       HOME
	   Used to find users config files.

       ENV Used by posix-compliant shells to specify a startup rc file.

       ZDOTDIR
	   Used to find user config files for zsh. If not set, defaults to HOME.

SEE ALSO

       surfraw(1), sh(1), ash(1), bash(1), dash(1), csh(1), tcsh(1), ksh(1), pdksh(1), zsh(1), rc(1), es(1)

AUTHOR

       Ian Beckwith <ianb@erislabs.net>

perl v5.12.4							    2011-07-12						    SURFRAW-UPDATE-PATH(1)
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