How to evaluate a variable name on LHS of expression?
I am trying to write a simple function to select values from a database and assign them to variables. It can have any number of arguments sent into it, and I want to assign the value retrieved to a different variable name for each argument sent in. So my code looks something like this:
I know the db2 statement works correctly. If I just run it once and hardocde the lefthand side with a variable name and then echo it out, it is selecting the proper value from the DB and assiging it correctly. But I can't get it to assign it to the parm name I send in. Essentially I need that $parm evaluated first to the parameter name and then used as the LHS of the expression. I have tried every quoting method I know of but can't get it to work. (this is Korn shell)
Probably a simple one.
Basically I am retrieving a number from a file - setting a variable against it and then incrementing this by 1 and using this as an entry number in a log file for messages. I need the variable to re-evalute itself each time I call it so I get the latest number in the file -... (1 Reply)
I have variables:
FOO="Text"
BAR="FOO"
I'd like to be able to evaluate the variable named as the value of $BAR.
echo $FOO
Text
echo $BAR
FOO
This is what I'd like to do:
echo ${$BAR} (this won't work)
Text (3 Replies)
Hello,
I have this:
#!/usr/bin/ksh
V1=ABC
str="hello 123;${V1}"
eval "echo $str"
i get
hello 123
/script.sh ABC not found
However eval works if $str variable doesn't contain a semicolumn (eg if str="hello 123~${v1}"
running the eval statement above would produce (2 Replies)
hi,
i'm reading a file "LISTE_FILE" like :
#
$LOGCOM * 5
$PRCCOM * 10
and i want to use the file with "while" and having the fields splitted into new variables for treatment :
while read LINE
do
# Ignorer les commentaires un # en premiere position
if
then... (3 Replies)
How to evaluate the value of a variable ?
For example:
a=var
$a=value !!!error happens!!!
I want to evaluate var=value, how to realize it?
Thanks!
---------- Post updated at 03:37 AM ---------- Previous update was at 02:22 AM ----------
I am using linux bash.
a=var
$a=value... (4 Replies)
I'm writing a script to merge the xkcd webcomic tiles for comic 1110. So far, I have written about 100 lines, and instead of doing each quadrant of the image separately, I've decided to use functions to do this, repeating for every quadrant and using variables for each quadrant to make the function... (9 Replies)
Hi
i tried to execute a below script but it is giving execution error
rec=ABC,1234,55.00
Colno=2
coldel=,
fd='"'$coldel'"'
fprint="'"'{print$'$colno'}'"'"
colsyn=`echo "echo "$rec "| awk -F"$fd $fprint`
echo column syntax is $colsyn
colrec=`colsyn`
echo column is $colrec (5 Replies)
Hi,
I am trying to set a variable that has time the format desired. And my intention is to echo variable (instead of actual date command) everytime I like to echo date. Please take a look at below code.
$NOW=''
echo $NOW
After 5 minutes
$echo $NOW
Issue here is , I am not... (2 Replies)
I want to create a conditional expression string and pass in an awk script. My script is as below...
comm="\$3 == "hello""
awk -F "^T" -v command="${comm}" ' {
if ( command ) { print "hye" }
}' testBut the statement "if ( command )" always evaluates to true which is not... (5 Replies)
I have to display only those subscribers which are in "unconnected state" and the date is 90 days older than today's date.
Below command is used for this purpose:
cat vfsubscriber_20170817.csv | sed -e 's/^"//' -e '1d' | \
nawk -F '",' '{if ( (substr($11,2,4) == 2017) && ( substr($11,2,8)... (1 Reply)
Discussion started by: dia
1 Replies
LEARN ABOUT OPENDARWIN
tcl_exprbooleanobj
Tcl_ExprLongObj(3) Tcl Library Procedures Tcl_ExprLongObj(3)__________________________________________________________________________________________________________________________________________________NAME
Tcl_ExprLongObj, Tcl_ExprDoubleObj, Tcl_ExprBooleanObj, Tcl_ExprObj - evaluate an expression
SYNOPSIS
#include <tcl.h>
int
Tcl_ExprLongObj(interp, objPtr, longPtr)
int
Tcl_ExprDoubleObj(interp, objPtr, doublePtr)
int
Tcl_ExprBooleanObj(interp, objPtr, booleanPtr)
int
Tcl_ExprObj(interp, objPtr, resultPtrPtr)
ARGUMENTS
Tcl_Interp *interp (in) Interpreter in whose context to evaluate string or objPtr.
Tcl_Obj *objPtr (in) Pointer to an object containing the expression to evaluate.
long *longPtr (out) Pointer to location in which to store the integer value of the expression.
int *doublePtr (out) Pointer to location in which to store the floating-point value of the expression.
int *booleanPtr (out) Pointer to location in which to store the 0/1 boolean value of the expression.
Tcl_Obj **resultPtrPtr (out) Pointer to location in which to store a pointer to the object that is the result of the expression.
_________________________________________________________________DESCRIPTION
These four procedures all evaluate an expression, returning the result in one of four different forms. The expression is given by the
objPtr argument, and it can have any of the forms accepted by the expr command.
The interp argument refers to an interpreter used to evaluate the expression (e.g. for variables and nested Tcl commands) and to return
error information.
For all of these procedures the return value is a standard Tcl result: TCL_OK means the expression was successfully evaluated, and
TCL_ERROR means that an error occurred while evaluating the expression. If TCL_ERROR is returned, then a message describing the error can
be retrieved using Tcl_GetObjResult. If an error occurs while executing a Tcl command embedded in the expression then that error will be
returned.
If the expression is successfully evaluated, then its value is returned in one of four forms, depending on which procedure is invoked.
Tcl_ExprLongObj stores an integer value at *longPtr. If the expression's actual value is a floating-point number, then it is truncated to
an integer. If the expression's actual value is a non-numeric string then an error is returned.
Tcl_ExprDoubleObj stores a floating-point value at *doublePtr. If the expression's actual value is an integer, it is converted to float-
ing-point. If the expression's actual value is a non-numeric string then an error is returned.
Tcl_ExprBooleanObj stores a 0/1 integer value at *booleanPtr. If the expression's actual value is an integer or floating-point number,
then they store 0 at *booleanPtr if the value was zero and 1 otherwise. If the expression's actual value is a non-numeric string then it
must be one of the values accepted by Tcl_GetBoolean such as ``yes'' or ``no'', or else an error occurs.
If Tcl_ExprObj successfully evaluates the expression, it stores a pointer to the Tcl object containing the expression's value at *resultP-
trPtr. In this case, the caller is responsible for calling Tcl_DecrRefCount to decrement the object's reference count when it is finished
with the object.
SEE ALSO
Tcl_ExprLong, Tcl_ExprDouble, Tcl_ExprBoolean, Tcl_ExprString, Tcl_GetObjResult
KEYWORDS
boolean, double, evaluate, expression, integer, object, string
Tcl 8.0 Tcl_ExprLongObj(3)