Hi,
i want to check if a variable var1 is not a or b or c
pseudo code:
If NOT (var1 = a or var1 = b or var1 = c)
then
...
fi
I want to use POSIX complaint Korn shell, and for string comparison
For the following code, logical.sh
I gave execute permissions to the script, however it only seems to run good when run by 'sh ' and not by the script itself.
We run all our jobs without specifying 'sh ' ahead
$ chmod 777 logical.sh
$ logical.sh
Var : j
./logical.sh[3]: syntax error at line 6 : `}' unexpected
$ sh logical.sh
Var : j
var not in the list
Var : b
var in the list
$
Where am i going wrong?
Is it necessary to enclose the variable in double quotes but not the literals on the other side of comparison operator?
Hi:confused:,
I have a file that contains :
+-----------------------------------------------------------------------------+
LABEL: super1_fix
EFIX FILES: 1
ABSTRACT: epkg for touch command
PRE-REQUISITES: no
PACKAGER VERSION: 7
REBOOT REQUIRED: no
BUILD BOOT... (4 Replies)
I'm would to create a script that would give me the results below.
Please note the spaces in the log file are actually commas(",".)
Log file Data
0:00 21:15 899 43 31 12 25.39
0:00 21:20 736 34 19 15 35.39
0:00 21:20 776 41 28 13 ... (3 Replies)
Please tell me how to nest logical expressions in bash. I would like to nest logical expressions for arguments of the "test" command on bash.
The following pseudo-code shows my intention.
// pseudo code
if (exp1 AND (exp2 OR exp3))
{
Output true;
}
else
{
Output false;
}
... (11 Replies)
Hello all. This is my first post/question on this site.
I’m a new Systems Analyst with previous experience with BASH. Although now I'm using AIX, and I’m trying to get a feel for the Korn shell (for those of you that don’t know AIX only uses the KORN shell).
I hope I put this into the correct... (10 Replies)
I have code as follows to perform some validations on C++ and Javascript files:
if || || ; then
However, when I want to add other extensions as well, say "py" or "sql", then the repeated OR starts to look contrived. I know I can use the -o operator to abbreviate the code a little bit, but... (14 Replies)
The POSIX shell standard grammar rules are at
Shell Command Language
I am trying to understand Rule 7 and I don't. I think there may be some mistakes there. I am not complaining about the standard; rather, I am concerned that my perception is wrong, and I don't understand something important.... (3 Replies)
Hi all...
This is more of a concensus question than help...
As many of you know I am experimenting with the limitations of Pure POSIX shell scripting.
Q: Is the directory /bin considered part of the Pure POSIX shell or must I stick entirely with the builtins only?
The reason is I... (2 Replies)
Hi all,
I am learning POSIX shell programming, and the book I read, uses the let command for integer arithmetic.
I have downloaded and use the shellcheck program on Linux.
This programs says:
In POSIX sh, 'let' is undefined.
See the screenshot attached.
What is the POSIX... (1 Reply)
Hi all...
This is just a fun project to see if it is possible to get a square root of a positive integer from 1 to 9200000 to 6 decimal places on a 64 bit architecture machine.
It is coded around dash and the results show the values from 0 to 10000.
Complex numbers can easily be catered for by... (3 Replies)
Hi all...
Apologies for any typos, etc...
This took a while but it didn't beat me...
Although there are many methods of generating random numbers in a POSIX shell this uses integer maths and a simple C source to create an executable to get epoch to microseconds accuracy if it is needed. I take... (8 Replies)
Discussion started by: wisecracker
8 Replies
LEARN ABOUT CENTOS
lksh
LKSH(1) BSD General Commands Manual LKSH(1)NAME
lksh -- Legacy Korn shell built on mksh
SYNOPSIS
lksh [-+abCefhiklmnprUuvXx] [-+o opt] [-c string | -s | file [args ...]]
DESCRIPTION
lksh is a command interpreter intended exclusively for running legacy shell scripts. It is built on mksh; refer to its manual page for
details on the scripting language. It is recommended to port scripts to mksh instead of relying on legacy or idiotic POSIX-mandated behav-
iour, since the MirBSD Korn Shell scripting language is much more consistent.
LEGACY MODE
lksh has the following differences from mksh:
o lksh is not suitable for use as /bin/sh.
o There is no explicit support for interactive use, nor any command line editing or history code. Hence, lksh is not suitable as a user's
login shell, either; use mksh instead.
o The KSH_VERSION string identifies lksh as ``LEGACY KSH'' instead of ``MIRBSD KSH''.
o lksh only offers the traditional ten file descriptors to scripts.
o lksh uses POSIX arithmetics, which has quite a few implications: The data type for arithmetics is the host ISO C long data type. Signed
integer wraparound is Undefined Behaviour. The sign of the result of a modulo operation with at least one negative operand is unspeci-
fied. Shift operations on negative numbers are unspecified. Division of the largest negative number by -1 is Undefined Behaviour. The
compiler is permitted to delete all data and crash the system if Undefined Behaviour occurs.
o The rotation arithmetic operators are not available.
o The shift arithmetic operators take all bits of the second operand into account; if they exceed permitted precision, the result is
unspecified.
o The GNU bash extension &> to redirect stdout and stderr in one go is not parsed.
o The mksh command line option -T is not available.
o Unless set -o posix is active, lksh always uses traditional mode for constructs like:
$ set -- $(getopt ab:c "$@")
$ echo $?
POSIX mandates this to show 0, but traditional mode passes through the errorlevel from the getopt(1) command.
o lksh, unlike AT&T UNIX ksh, does not keep file descriptors > 2 private.
SEE ALSO mksh(1)
https://www.mirbsd.org/mksh.htm
https://www.mirbsd.org/ksh-chan.htm
CAVEATS
lksh tries to make a cross between a legacy bourne/posix compatibl-ish shell and a legacy pdksh-alike but ``legacy'' is not exactly speci-
fied.
The set built-in command does not have all options one would expect from a full-blown mksh or pdksh.
Talk to the MirOS development team using the mailing list at <miros-mksh@mirbsd.org> or the #!/bin/mksh (or #ksh) IRC channel at
irc.freenode.net (Port 6697 SSL, 6667 unencrypted) if you need any further quirks or assistance, and consider migrating your legacy scripts
to work with mksh instead of requiring lksh.
MirBSD May 2, 2013 MirBSD