Ok i see you had did a read -p 'Please type ation:' x, that is not visible here .
You can either make sure the provided char inputs are non-caps, or use regex to catch both at once.
1) Make it small (is this posix?)
Code:
x=A
x=${x,,}
[ $x = a ] && echo "Add"
2) Or use Regex:
Code:
x=a
[ $x = [aA] ] && echo "Add"
Use either 1. or 2., this will save you from using if [ $x == 'B' -o $x == 'b' ] ; then for each of the A-F.
3) For menus or comparing 1 value with diffrent options, its quite easier to use a case statement
Code:
case $x in
a) echo "do add" ;;
b) echo "do sub" ;;
esac
4) Could use Regex here too (= instead)
Code:
case $x in
a|A) echo "do add" ;;
[bB]) echo "do sub" ;;
esac
edit: 5. Quotes:
I'd rather make the quotes around the variables, than around the letters.
If the variable is empty, or contains a special char (like arrow-up) it will produce and error message, rather than just not execute (as in not true ; not matching).
Given this one long stream of data (all one line):
<TransactionDetail><TransactionHeader><ErrorLogging>YES</ErrorLogging><HistoryLogging>YES</HistoryLogging><ErrorDetection>NO</ErrorD... (4 Replies)
Hi!
Suppose I am at a location xyz:/abc1/abc2/abc3
Is it possible to move to another location xyz:/mnl1/mnl2/mnl3
by some coding within a script? (5 Replies)
I'm just starting a 'serious' coding in UNIX, so what I need is to run a C code on UNIX, What do I have to install (app) prior to coding/running the code and how do I compile that code?
can I write my c code in UNIX or I need to have a visual studio for this? (7 Replies)
Hi,
I have very little knowledge with unix and pmcmd. I need help with a issue.
I have to see whether a file has been dropped in a particular location/path. If the file dropped I have to check the last modified time, which should be greater than 8pmEST the prior day. If the file has been... (4 Replies)
I have a file f1.txt that contains string:
f1.txt
aaa
bbb
ccc
...
I want to write code to search that each string in file f2.txt(this file contains 1000+line codes).
file f2.txt
..
..
....aaa...xyz..
...
...
...ppp...
(dots . can be characters ot blank spaces)
If particular... (2 Replies)
Unix script coding help?
i am trying to write a code that will display following menu to user:
(A) Add
(B) Subtract
(C) Multiply
(D) Divide
(E) Modulus
(F) Exponentiation
(G) Exit
Then ask user for choice (A-F). After taking users choice ask user for two numbers and
perform... (3 Replies)
Good afternoon everyone,
I am very new to UNIX shell scripting and I am trying to understand the following code. I know what it does but I need to modify it so it will allow me to pass a file name as *FILENAME*
Thank for any guidance offered.
if ] ; then
match=`expr "$file" :... (2 Replies)
Hi,
as I mentioned in this thread(https://www.unix.com/shell-programming-and-scripting/280737-awk-function-return-permutations-n-items-out-m.html), a helpful coding style may improve overall value and support for people who come here and want to learn things the participants from unix.com have... (2 Replies)
Discussion started by: stomp
2 Replies
LEARN ABOUT REDHAT
catch
catch(n) Tcl Built-In Commands catch(n)
__________________________________________________________________________________________________________________________________________________NAME
catch - Evaluate script and trap exceptional returns
SYNOPSIS
catch script ?varName?
_________________________________________________________________DESCRIPTION
The catch command may be used to prevent errors from aborting command interpretation. Catch calls the Tcl interpreter recursively to exe-
cute script, and always returns without raising an error, regardless of any errors that might occur while executing script.
If script raises an error, catch will return a non-zero integer value corresponding to one of the exceptional return codes (see tcl.h for
the definitions of code values). If the varName argument is given, then the variable it names is set to the error message from interpret-
ing script.
If script does not raise an error, catch will return 0 (TCL_OK) and set the variable to the value returned from script.
Note that catch catches all exceptions, including those generated by break and continue as well as errors. The only errors that are not
caught are syntax errors found when the script is compiled. This is because the catch command only catches errors during runtime. When
the catch statement is compiled, the script is compiled as well and any syntax errors will generate a Tcl error.
EXAMPLES
The catch command may be used in an if to branch based on the success of a script.
if { [catch {open $someFile w} fid] } {
puts stderr "Could not open $someFile for writing
$fid"
exit 1
}
The catch command will not catch compiled syntax errors. The first time proc foo is called, the body will be compiled and a Tcl error will
be generated.
proc foo {} {
catch {expr {1 +- }}
}
KEYWORDS
catch, error
Tcl 8.0 catch(n)
03-25-2014
.