I have below code, that check abcd that is fine, when it not find abcd it check for 1 minutes that is also fine but i want one enhancement when it failed at the end it print "please check again" but if i add this line after fi statement it is constantly printing, i don't want that, please suggest.
Last edited by learnbash; 11-05-2013 at 01:13 PM..
Sorry for such a dreadful title, but I'm not sure how to be more descriptive. I'm hoping some of the more gurutastic out there can take a look at a solution I came up with to a problem, and advice if there are better ways to have gone about it.
To make a long story short around 20K pieces of... (2 Replies)
I'm trying to understand if it's possible to create a set of variables that are numbered based on another variable (using eval) in a loop, and then call on it before the loop ends.
As an example I've written a script called question (The fist command is to show what is the contents of the... (2 Replies)
Hi Im running this script, which is supposed to find the max value build some tables and then stop running once all the tables are built. Thing is , it keeps assigning a null value to $h and then $g is null so it keep building tables i.e. testupdateNUL. How can I stop this? Here is what I have:
... (4 Replies)
Hi all
Sorry for the basic question, but i am writing a shell script to get around a slightly flaky binary that ships with one of our servers. This particular utility randomly generates the correct information and could work first time or may work on the 12th or 100th attempt etc !.... (4 Replies)
Hi,
hope I am posting in the right section.
My problem is that I have 2 or more arguments passed and I want to check if the arguments passed exists or not.
The first argument should not exist and the remaining others should exist.
example:
./shells.sh argument1 argument2 argument3
... (5 Replies)
Hi, I was debating if I should put this in the dummies or scripts section, I apologize in advance if I chose poorly.
Fairly new to Unix and BASH scripting but I thought I made it fairly well given my limited understanding. However, the output indicates that it's looping and I'm ending up with a... (5 Replies)
Hello All,
Maybe I'm Missing something here but I have NOOO idea what the heck is going on with this....?
I have a Variable that contains a PATTERN of what I'm considering "Illegal Characters". So what I'm doing is looping
through a string containing some of these "Illegal Characters". Now... (5 Replies)
Hi,
I want to read file multiple times. Right now i am using while loop but that is not working.
ex.
While read line
do
while read line2
do
echo stmt1
#processing some data based on data.,
done < file2.txt
done < file1.txt # This will have 10... (4 Replies)
Hi all,
i developed a script to measure the uptime of a process in a Solaris 10/11 environments.
All is well, but i came across a situation where there are multiple processes of the same name. Basically i have the following result file:
beVWARS 13357 19592122
beVWARS 14329 19591910... (4 Replies)
Discussion started by: nms
4 Replies
LEARN ABOUT REDHAT
system
SYSTEM(3) Linux Programmer's Manual SYSTEM(3)NAME
system - execute a shell command
SYNOPSIS
#include <stdlib.h>
int system(const char *string);
DESCRIPTION
system() executes a command specified in string by calling /bin/sh -c string, and returns after the command has been completed. During
execution of the command, SIGCHLD will be blocked, and SIGINT and SIGQUIT will be ignored.
RETURN VALUE
The value returned is -1 on error (e.g. fork failed), and the return status of the command otherwise. This latter return status is in the
format specified in wait(2). Thus, the exit code of the command will be WEXITSTATUS(status). In case /bin/sh could not be executed, the
exit status will be that of a command that does exit(127).
If the value of string is NULL, system() returns nonzero if the shell is available, and zero if not.
system() does not affect the wait status of any other children.
CONFORMING TO
ANSI C, POSIX.2, BSD 4.3
NOTES
As mentioned, system() ignores SIGINT and SIGQUIT. This may make programs that call it from a loop uninterruptable, unless they take care
themselves to check the exit status of the child. E.g.
while(something) {
int ret = system("foo");
if (WIFSIGNALED(ret) &&
(WTERMSIG(ret) == SIGINT || WTERMSIG(ret) == SIGQUIT))
break;
}
Do not use system() from a program with suid or sgid privileges, because strange values for some environment variables might be used to
subvert system integrity. Use the exec(3) family of functions instead, but not execlp(3) or execvp(3). system() will not, in fact, work
properly from programs with suid or sgid privileges on systems on which /bin/sh is bash version 2, since bash 2 drops privileges on
startup. (Debian uses a modified bash which does not do this when invoked as sh.)
The check for the availability of /bin/sh is not actually performed; it is always assumed to be available. ISO C specifies the check, but
POSIX.2 specifies that the return shall always be non-zero, since a system without the shell is not conforming, and it is this that is
implemented.
It is possible for the shell command to return 127, so that code is not a sure indication that the execve() call failed.
SEE ALSO sh(1), signal(2), wait(2), exec(3)
2001-09-23 SYSTEM(3)