Hi,
I have a shell script to build components of a product. The follow snippet will explain what I am doing.
# !/bin/sh
for choice in "$@" ;
do
case $choice in
"o") echo "Calling $choice" ; o ;;
"i") echo... (8 Replies)
I have input file with below content:
Person:
Name: Firstname1 lastname1
Address: 111, Straat
City : Hilversum
Person:
Name : Fistname2 lastname2
Address: 222, street
Cit: Bussum
Person:
Name : Firstname2 lastname3
Address: 333, station straat
City: Amsterdam
I need... (6 Replies)
Hi,
echo "Enter file name of input file list along with absolute path : "
read inputFileList
if
then
for string in `cat inputFileList`
do
echo $string
done
else
echo " file does not exist"
fi
From the above code, if the user enters a invalid file... (1 Reply)
I have code that accepts input from a user, and when the user hits enter it is supposed to delete that whole line from the file.
echo "Which record? "
read record
sed '/$record/d' file
However, it does not delete it. Any help? (1 Reply)
i have a script which takes input from user, if user gives either Y/y then it should continue, else it should quit by displaying user cancelled.
#!/bin/sh
echo " Enter your choice to continue y/Y OR n/N to quit "
read A
if
then
echo " user requested to continue "
##some commands... (7 Replies)
Good Evening. I'm new to C. Can you please help me.
I'm creating an error checking function, user will input a string, this will check if the input is all alphabet or all letters only. If there is a digit or other special char, it will print Error then ask input from user again.
Here's my... (1 Reply)
I am trying to allow a user to enter in text and then store that text in a variable $gene to run in an awk command in which those values are used to run some calculations. I am getting syntax errors however, when I try. Thank you :).
The awk runs great if it is a pre-defined file that is used,... (7 Replies)
i am having file like this
#!/bin/bash
read -p 'Username: ' uservar
match='<color="red" />'
text='this is only a test
so please be patient
<color="red" />'
echo "$text" | sed "s/$match/&$uservar\g"
so desireble output what i want is if user type MARIA
this is only a test
so please... (13 Replies)
Discussion started by: tomislav91
13 Replies
LEARN ABOUT OSX
eval
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)