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Full Discussion: If else with one variable
Top Forums Shell Programming and Scripting If else with one variable Post 302918407 by sea on Tuesday 23rd of September 2014 06:33:59 AM
Old 09-23-2014
I'm a bit confused now...

Quote:
Originally Posted by Don
If an empty line is entered, it will expand to [ -z ] which will yield TRUE because "-z" is not an empty string (not because $line expands to an empty string).

If a single word is entered (and it does not contain any pattern matching characters that would match more than one file in the current directory), then it will expand to [ -z word ] which will evaluate to TRUE as expected.
Now i belived -z is testing if argument is empty.
Thus, expecting that an empty line (variable in general) returns true.

Code:
 ~ $ line=" "
+ ~ $ [ -z "$line" ] && echo empty
 ~ $ [ -z $line ] && echo empty
:( ~ $

However, i got the 'multiple expanding part'...
Code:
 ~ $ line=$(ls)
:) ~ $[ -z $line ] && echo empty
bash: [: too many arguments
2 ~ $

So in conclusion, the quotes around make it less error prone, but it doesnt matter whether or not the variable contains spacechar.
Truely a standards guy you are, me gotta get used again to do quotes around there again Smilie

Thank you Don.
 

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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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