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Full Discussion: ksh using `` or $()
Top Forums Shell Programming and Scripting ksh using `` or $() Post 302471651 by DGPickett on Sunday 14th of November 2010 12:57:34 PM
Old 11-14-2010
Yes in general unless you are exploding a list, $xxx s/b "$xxx" so embedded blanks or total blankness does not invalidate what you say. I even use quotes on constants, both for a sort of parity, to tell the reader it is a constant not a variable, command or other meta-word of some sort:
Code:
if [ "$xxx" = "true" ]
 then
  echo "Variable '$xxx' is 'true'!"
 fi

BTW, any time I find myself wanting to say 'elif' anywhere, I go to 'case' not 'if'. The case operator has a nice, clear structure showing the precedence of tests and the logical 1 of all cases being addressed in the design. It provides nice opportunities to hang comments, too.

In this case, 'case' also allows you to test the $f variable without fork, exec, pipe, print or awk. Also, the if [[]] has both kinds of pattern matching native in the shell.

Either 'case', or as I suggested above, a sequence of if's that, if true, terminate the flow with exit or return. My personal term for that sort of tree collapse is 'cut them off at the pass' (prevent complexity by early pruning of odd cases like error). Putting such in some sort of script or function ensures you can leave early, as soon as you have an answer, however negative or unlikely in real life, and then proceed to the finer points of your functionality free of those worries.

Last edited by DGPickett; 11-14-2010 at 02:09 PM..
 

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fmt(1)							      General Commands Manual							    fmt(1)

NAME
fmt - format text SYNOPSIS
width] [file...] DESCRIPTION
The command is a simple text formatter that fills and joins lines to produce output lines of (up to) the number of characters specified in the width option. The default width is 72. concatenates the arguments. If none are given, formats text from the standard input. Blank lines are preserved in the output, as is the spacing between words. does not fill lines beginning with a period for compatibility with Nor does it fill lines starting with Indentation is preserved in the output and input lines with differing indentation are not joined (unless is used). can also be used as an in-line text filter for the command: reformats the text between the cursor location and the end of the paragraph. Options recognizes the following options: Crown margin mode. Preserve the indentation of the first two lines within a paragraph and align the left margin of each subsequent line with that of the second line. This is useful for tagged paragraphs. Split lines only. Do not join short lines to form longer ones. This prevents sample lines of code, and other such "formatted" text, from being unduly combined. Fill output lines to up to width columns. WARNINGS
The width option is acceptable for BSD compatibility, but it may go away in future releases. SEE ALSO
nroff(1), vi(1). fmt(1)
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