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Full Discussion: A difficult script (for me)
Top Forums Shell Programming and Scripting A difficult script (for me) Post 302156168 by gus2000 on Monday 7th of January 2008 12:46:40 PM
Old 01-07-2008
First, you won't get variable substitution inside single-quotes:

Code:
# x=123
# echo 'x=$x'       # string is literal
x=$x

# echo "x=$x"       # string is evaluated by the shell
x=123

# echo "x='$x'"
x='123'

Single-quotes lose their special quoting superpowers when inside double-quotes.

Also, if you pass a string to a command that includes a dash ("-") you run the risk of the string being interpreted as flags. You should therefore use the double-dash to indicate that no more flags are coming:

Code:
grep -c -v -- "$string" $file

So if "$string" includes any dashes, they will be ignored since they are after the "--".
 

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LEARN ABOUT MOJAVE

tcl_allowexceptions

Tcl_AllowExceptions(3)					      Tcl Library Procedures					    Tcl_AllowExceptions(3)

__________________________________________________________________________________________________________________________________________________

NAME

       Tcl_AllowExceptions - allow all exceptions in next script evaluation

SYNOPSIS

       #include <tcl.h>

       Tcl_AllowExceptions(interp)

ARGUMENTS

       Tcl_Interp *interp (in)		Interpreter in which script will be evaluated.
_________________________________________________________________

DESCRIPTION

       If  a  script is evaluated at top-level (i.e. no other scripts are pending evaluation when the script is invoked), and if the script termi-
       nates with a completion code other than TCL_OK, TCL_ERROR or TCL_RETURN, then Tcl normally converts this into a TCL_ERROR  return  with	an
       appropriate  message.  The particular script evaluation procedures of Tcl that act in the manner are Tcl_EvalObjEx, Tcl_EvalObjv, Tcl_Eval,
       Tcl_EvalEx, Tcl_GlobalEval, Tcl_GlobalEvalObj, Tcl_VarEval and Tcl_VarEvalVA.

       However, if Tcl_AllowExceptions is invoked immediately before calling one of those a procedures, then arbitrary completion codes  are  per-
       mitted from the script, and they are returned without modification.  This is useful in cases where the caller can deal with exceptions such
       as TCL_BREAK or TCL_CONTINUE in a meaningful way.

KEYWORDS

       continue, break, exception, interpreter

Tcl									7.4						    Tcl_AllowExceptions(3)
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