This is how i see my code working with the file descriptors and pipes and well every thing. Take a look at the picture to see what i am talking about, it is very descriptive and took a long time to do in paint so please take a look.
I have a simple script that I want to run every 30 minutes but only when I execute it. I don't want it to be a crontab job.
so i have for example
date
ls -l
who
sleep 1800
The first time it executes correctly but after the first time it nevers execute back again. It should execute after... (2 Replies)
Anyone have an idea why this if statement does not work correctly?
"test2.sh" 18 lines, 386 characters
#!/usr/bin/sh
WARNING=80
CRITICAL=95
check_it()
{
if ] || ];then
echo "YES ] || ]"
else
echo "NO ] || ]"
fi
}
check_it 80.1
check_it 81.1 (3 Replies)
Hi,
I have a script where I am trying to set a local variable using the following,
MYVAR="$NAME"_"$NAME2".txt
where say,
NAME = one
NAME2 = two
so I want the output one_two.txt but what I am getting is,
two.txt
basically the $NAME2 is overwriting, what am I doing wrong?
... (3 Replies)
egrep -A 7 -m 2 -h 'Date:|Time:' *.html
this is showing only 2 line after the context of the 2nd found match. Is this a bug in grep?
egrep -A 7 -m 2 -h 'Time:' *.html - this works correctly (2 Replies)
I am trying to copy 2 types of files so I can archive them. I tested with a set of commands:
touch -t $(date -d "-60 day" +%Y%m%d) WORKDIR/REF
find TARGETDIR/ -type f -maxdepth 1 -iname \*.out\* -or -iname \*.log\* ! -newer WORKDIR/REF -exec ls -l {} \;
This correctly lists any files in the... (2 Replies)
We are using Red Hat linux system.
I am transferring my rman backup files to another server.
Here is the command i am using to transfer the files.
/usr/bin/rsync -avpP --delete /xyz/xyz/ 99.99.999.99::db110bkp
Here is the rsync version.
>rsync --version
rsync version 3.0.6 ... (1 Reply)
Consider the following code:
grep -o -e '^STEAM_::\d+$' workfile3.tmp
A sample format of a valid string for the regexp would be:
STEAM_0:1:12345678
Here is an example line from the workfile3.tmp file:
465:L 01/02/2012 - 00:05:33: "Spartan1-1-7<8><STEAM_0:1:47539638><>" connected
No... (2 Replies)
Hi
I am attempting to right a script which will read a table and extract specfic information.
LASTFAILEDJOB=/usr/openv/netbackup/scripts/GB-LDN/Junaid/temp_files/lastfailedjob
cat /usr/openv/netbackup/scripts/GB-LDN/Junaid/temp_files/lastfailedjob
237308646
If i run the following... (5 Replies)
Hello All,
Yesterday, all day, I was using x11vnc and vncviewer to connect to a server. But today for some reason it is not working. I don't
remember changing any settings or anything like that, but because it stopped working correctly I guess something has...?
I'm issuing the exact same... (0 Replies)
Today I saw the topic. sum-even-numbers-1-100 At that time, it was already closed but not the point. Other thoughts came to mind.
All newcomers to Haskell are afraid that when they study it, their brains will turn inside out. I did not notice anything like that. And all because the brains of all... (4 Replies)
Discussion started by: nezabudka
4 Replies
LEARN ABOUT REDHAT
dup
DUP(2) Linux Programmer's Manual DUP(2)NAME
dup, dup2 - duplicate a file descriptor
SYNOPSIS
#include <unistd.h>
int dup(int oldfd);
int dup2(int oldfd, int newfd);
DESCRIPTION
dup and dup2 create a copy of the file descriptor oldfd.
After successful return of dup or dup2, the old and new descriptors may be used interchangeably. They share locks, file position pointers
and flags; for example, if the file position is modified by using lseek on one of the descriptors, the position is also changed for the
other.
The two descriptors do not share the close-on-exec flag, however.
dup uses the lowest-numbered unused descriptor for the new descriptor.
dup2 makes newfd be the copy of oldfd, closing newfd first if necessary.
RETURN VALUE
dup and dup2 return the new descriptor, or -1 if an error occurred (in which case, errno is set appropriately).
ERRORS
EBADF oldfd isn't an open file descriptor, or newfd is out of the allowed range for file descriptors.
EMFILE The process already has the maximum number of file descriptors open and tried to open a new one.
WARNING
The error returned by dup2 is different to that returned by fcntl(..., F_DUPFD, ...) when newfd is out of range. On some systems dup2 also
sometimes returns EINVAL like F_DUPFD.
CONFORMING TO
SVr4, SVID, POSIX, X/OPEN, BSD 4.3. SVr4 documents additional EINTR and ENOLINK error conditions. POSIX.1 adds EINTR.
SEE ALSO fcntl(2), open(2), close(2)Linux 1.1.46 1994-08-21 DUP(2)