07-15-2009
If I understand correctly you don't need eval/variable and you don't need cat at all. Search your shell man pages for command substitution. You just need to format and spool the output (using printf, for example).
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi guy,
I have a problem to pass a variable containing '*' value to FIND command.
below is the script. It doesn't work by submit below command:
rmf.sh name '*.txt'
or
rmf.sh name *.txt
I've tried either optn="-name '$2'" or optn="-name $2"., and there is no luck.
### (script... (5 Replies)
Discussion started by: unxuser
5 Replies
2. Debian
Hi All,
I am running my application on a dual cpu debian linux 3.0 (2.4.19 kernel).
For my application:
<sar -U ALL>
CPU %user %nice %system %idle
...
10:58:04 0 153.10 0.00 38.76 0.00
10:58:04 1 3.88 0.00 4.26 ... (0 Replies)
Discussion started by: jaduks
0 Replies
3. Shell Programming and Scripting
how do I feed output of "wc" to a shell script variable "countBcp"? (2 Replies)
Discussion started by: devy
2 Replies
4. Shell Programming and Scripting
Hi All,
I need to store the real seconds of the following command in a variable. How could it be done?
time $(dd if=/dev/zero of=/dev/sda1 bs=512 count=2048;sync)
Thanks,
Amio (12 Replies)
Discussion started by: amio
12 Replies
5. Shell Programming and Scripting
I intend to find the path/full location of a file(filename given by user thru "read filenme") using "find" or any other command and then store it's output in a variable for some other processing.
But struggling to put all things together (i.e finding the fully qualified location of that file and... (4 Replies)
Discussion started by: punitpa
4 Replies
6. UNIX for Dummies Questions & Answers
When I do a listing in one particular directory (ls -al) I get:
total 43456
drwxrwxrwx 2 root root 4096
drwxrwxrwx 3 root root 4096
-rwxrwxr-x 1 nobody nobody 3701594
-rwxrwxr-x 1 nobody nobody 3108510
-rwxrwxr-x 1 nobody nobody 3070580
-rwxrwxr-x 1 nobody nobody 3099733
-rwxrwxr-x 1... (1 Reply)
Discussion started by: proactiveaditya
1 Replies
7. Shell Programming and Scripting
Hi All,
I have working (Perl) code to combine 2 input files into a single output file using the join function that works to a point, but has the following limitations:
1. I am restrained to 2 input files only.
2. Only the "matched" fields are written out to the "matched" output file and... (1 Reply)
Discussion started by: Katabatic
1 Replies
8. Shell Programming and Scripting
Hi all,
I am new to Linux/shell scripting having moderate knowledge.
In my script, I need to get execution time of a command (say 'ls') in mili seconds level. For this i tried using "time" command to retrieve the total execution time in milli seconds. But, the problem is that, how to save... (9 Replies)
Discussion started by: happening_linux
9 Replies
9. Shell Programming and Scripting
Hello,
There's a third-party application's command that shows the application's status like "tail -f verybusy.log". When use the command, the output comes every 1-sec. but when it goes in a script below the output comes every 8-sec...What is the problem and how can I fix it?
open(CMD,... (2 Replies)
Discussion started by: Shawn, Lee
2 Replies
10. Shell Programming and Scripting
Hi All,
I am new here but I have a scripting question that I can't seem to figure out with the "find" cmd.
What I am trying to do is to only have to run a single find cmd parsing the directories and output the different file types to induvidual files and I have been running into problems.... (3 Replies)
Discussion started by: swaters
3 Replies
eval(n) Tcl Built-In Commands eval(n)
__________________________________________________________________________________________________________________________________________________
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(n), concat(n), error(n), interp(n), list(n), namespace(n), subst(n), tclvars(n), uplevel(n)
KEYWORDS
concatenate, evaluate, script
Tcl eval(n)