07-23-2014
Never use eval if you can possibly avoid it. If your file contains `rm -Rf ~/` and you feed that text into eval, eval will execute that code!
You explained one tiny corner of one tiny corner of your problem. What exactly is this line-by-line loader thing for? Is it a part of anything larger?
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
This is a totally dumb newbie question, but I have not been able to find t he answer in the BASH book or online.
I am trying pass a double quoted variable to the command line.
variable = "-b \"dc=example,dc=com\""
When I run sh -x the variable comes out as '-b "dc=example,dc=com"' is... (4 Replies)
Discussion started by: burton_1080
4 Replies
2. Shell Programming and Scripting
Hi,
I am generating html code using cshell, but i am having one problem while printing double quotes,
I need to write following code in file. where $var contains list of web address
<a href="$var">$var</a>
So i am using
echo "<a href="$var">$var</a>" > file.html
But with this " in... (4 Replies)
Discussion started by: sarbjit
4 Replies
3. Shell Programming and Scripting
I have lines with:
elseif (req.http.host ~ "^(www.)?edificationtube.com$|www.edificationtube.org www.edificationtube.net edificationtube.org www.edificationtube.com edificationtube.net") {
elseif (req.http.host ~ "^(www.)?collegecontender.com$|www.collegecontender.com collegecontenders.com... (3 Replies)
Discussion started by: EXT3FSCK
3 Replies
4. UNIX for Dummies Questions & Answers
Hi i have to insert the below line into a specific line number of another file
export MBR_CNT_PRCP_TYPE_CODES_DEL="'01','02','04','05','49','55','UNK'"
I have passed the above line to a variable say ins_line. I have used below command to perform the insert
awk 'NR==3{print "'"${ins_line}"'"}1'... (1 Reply)
Discussion started by: sathishteradata
1 Replies
5. Shell Programming and Scripting
I need to interpolate a shell variable in a code, i cannot share the exact code so this is an example i made up to describe the situation
What I am trying to do here is try to wrap up the value of a variable in single quotes. This value needs to be passed to another program which would only... (4 Replies)
Discussion started by: sam05121988
4 Replies
6. Shell Programming and Scripting
HI Guys,
I want to echo below line in my file :-
lpd | grep AL | nawk '{print "1dLA - " $0}
How can i echo same Output (4 Replies)
Discussion started by: pareshkp
4 Replies
7. UNIX for Dummies Questions & Answers
As the title says I'm running a korn script in attempts to find an exact match in named.conf
finddomain.ksh
#!/bin/ksh
#
echo "********** named.conf ************"
file=/var/named/named.conf
for domain in `cat $1`
do
grep -n '"\$domain "' $file
done
echo "********** thezah.inc... (1 Reply)
Discussion started by: djzah
1 Replies
8. Shell Programming and Scripting
Hi All,
OS - Suse 10
ksh --version
version sh (AT&T Research) 93s+ 2008-01-31
I am passing two words within double quotes ("Application Developer") to script as variable, but script is adding two single quotes between two words like ("Application' 'Developer").
below is simple test... (4 Replies)
Discussion started by: srimitta
4 Replies
9. Shell Programming and Scripting
I am unable to expand the value of entry variable inside the nawk command.
I tried three different nawk command as below but none of them substitute the value of entry variable.
ls *.txt | while IFS='' read -r entry; do
#nawk '/<name>/{A=1;++i} A{print >> ("cmd"i"_"$entry)}... (9 Replies)
Discussion started by: mohtashims
9 Replies
10. Shell Programming and Scripting
Hi got this issue and was wondering if someone could please help out ?
var='." "'
echo $var
." "
I 'll get ." " and not ." with 10 spaces in between "
Thanks (3 Replies)
Discussion started by: stinkefisch
3 Replies
eval(3tcl) Tcl Built-In Commands eval(3tcl)
__________________________________________________________________________________________________________________________________________________
NAME
eval - Evaluate a Tcl script
SYNOPSIS
eval arg ?arg ...?
_________________________________________________________________
DESCRIPTION
Eval takes one or more arguments, which together comprise a Tcl script containing one or more commands. Eval concatenates all its argu-
ments in the same fashion as the concat command, passes the concatenated string to the Tcl interpreter recursively, and returns the result
of that evaluation (or any error generated by it). Note that the list command quotes sequences of words in such a way that they are not
further expanded by the eval command.
EXAMPLES
Often, it is useful to store a fragment of a script in a variable and execute it later on with extra values appended. This technique is
used in a number of places throughout the Tcl core (e.g. in fcopy, lsort and trace command callbacks). This example shows how to do this
using core Tcl commands:
set script {
puts "logging now"
lappend $myCurrentLogVar
}
set myCurrentLogVar log1
# Set up a switch of logging variable part way through!
after 20000 set myCurrentLogVar log2
for {set i 0} {$i<10} {incr i} {
# Introduce a random delay
after [expr {int(5000 * rand())}]
update ;# Check for the asynch log switch
eval $script $i [clock clicks]
}
Note that in the most common case (where the script fragment is actually just a list of words forming a command prefix), it is better to |
use {*}$script when doing this sort of invocation pattern. It is less general than the eval command, and hence easier to make robust in |
practice. The following procedure acts in a way that is analogous to the lappend command, except it inserts the argument values at the
start of the list in the variable:
proc lprepend {varName args} {
upvar 1 $varName var
# Ensure that the variable exists and contains a list
lappend var
# Now we insert all the arguments in one go
set var [eval [list linsert $var 0] $args]
}
However, the last line would now normally be written without eval, like this: |
set var [linsert $var 0 {*}$args] |
SEE ALSO
catch(3tcl), concat(3tcl), error(3tcl), interp(3tcl), list(3tcl), namespace(3tcl), subst(3tcl), tclvars(3tcl), uplevel(3tcl)
KEYWORDS
concatenate, evaluate, script
Tcl eval(3tcl)