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Full Discussion: two while nested loops
Top Forums Shell Programming and Scripting two while nested loops Post 302691069 by Chubler_XL on Thursday 23rd of August 2012 09:17:29 PM
Old 08-23-2012
The nested for loops are fine and are quite efficient as they are implemented within the shell. The trick here is to avoid calling the external command (nc) more times than is necessary.

As an example if you are just looking for open ports, you would gain a heap of performance by using the nc -z option and call nc once for the whole set of ports eg:

Code:
# nc -z host.example.com 25,80,5900-5910
Connection to host.example.com 25 port [tcp/smtp] succeeded!
Connection to host.example.com 5900 port [tcp/vnc] succeeded!

But, of course, this is different functionality and comes under requirements optimization, not code tweaking.
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set_color(1)							       fish							      set_color(1)

NAME
set_color - set_color - set the terminal color set_color - set the terminal color Synopsis set_color [-v --version] [-h --help] [-b --background COLOR] [COLOR] Description Change the foreground and/or background color of the terminal. COLOR is one of black, red, green, brown, yellow, blue, magenta, purple, cyan, white and normal. o -b, --background Set the background color o -c, --print-colors Prints a list of all valid color names o -h, --help Display help message and exit o -o, --bold Set bold or extra bright mode o -u, --underline Set underlined mode o -v, --version Display version and exit Calling set_color normal will set the terminal color to whatever is the default color of the terminal. Some terminals use the --bold escape sequence to switch to a brighter color set. On such terminals, set_color white will result in a grey font color, while set_color --bold white will result in a white font color. Not all terminal emulators support all these features. This is not a bug in set_color but a missing feature in the terminal emulator. set_color uses the terminfo database to look up how to change terminal colors on whatever terminal is in use. Some systems have old and incomplete terminfo databases, and may lack color information for terminals that support it. Download and install the latest version of ncurses and recompile fish against it in order to fix this issue. Version 1.23.1 Sun Jan 8 2012 set_color(1)
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