Hi ,
I am having one situation in which I need to run some simple unix commands after doing "chroot" command in a shell script. Which in turn creates a new shell.
So scenario is that
- I need to have one shell script which is ran as a part of crontab
- in this shell script I need to do a... (2 Replies)
Is it ok to use exit() inside a signal handler?
I catch SIGUSR1 in a signal handler and I try to close a file and then exit. The result is inconsistent. Sometimes the process exit and sometimes it returns to the original state before the signal handler was invoked.
Perhaps exit is not legal in... (8 Replies)
Dears,
I'm new in shell scripting and i need your help, i would like to know how can i create a script to ftp to a certain unix/linux machine/server IP address and get a file for example without user intervention? How can i force the script to use a certain username and password to access this... (4 Replies)
When my script deals with large input files like 22Gb or 18 GB the basic commands like sort or join fails when run from inside the shell scripts. Can there be any specific reason for this?
For e.g.
sort -u -t "," -k1,1 a.csv > a.csv.uniq"
sort -u -t "," -k1,1 b.csv > b.csv.uniq"
The... (3 Replies)
How can I find the biggest file in a branch?
I tried
find / \*.\* | xargs du | sort -n 1,1 | head 1
but shell do nothings :(
---------- Post updated at 03:07 PM ---------- Previous update was at 02:41 PM ----------
Solved:
find / -name \*.\* | xargs du | sort -nr | head -n 1 (0 Replies)
I have a program dnapars
I execute the program from command line as following:
./dnapars
The program then prompts me some message as a user menu from where I have to select a series of options in the order R U Y R. And then I copy the output file (outfile) in another result file.
I wrote the... (3 Replies)
I would like to execute a commands in four different servers through ssh at a single instance(simultaneously).
Below are the details with examples,
ssh user1@server1 "grep xxxx logs"
ssh user1@server2 "grep xxxx logs"
ssh user1@server3 "grep xxxx logs"
Each statement will take some... (4 Replies)
Hi,
I have coded a program in Haskell using the compiler Hugs and the program requires multiple commands (with parameters) to be entered into it, it then outputs the result of its execution. I need to test a lot of different options (i.e. the parameters) so it would be obvious to automate the... (0 Replies)
Hello
I'm trying to write simple script to delete archive logs for RMAN, unfortunately it's not working, I tried two way to do that:
#!/bin/ksh
echo "Start ....."
rman target=/ << EOF
RUN {
delete force noprompt archivelog until time 'sysdate-10';
}
EXIT;
EOF
echo "END ..."
echo... (6 Replies)
Discussion started by: samer.odeh
6 Replies
LEARN ABOUT LINUX
bswap_16
BSWAP(3) Linux Programmer's Manual BSWAP(3)NAME
bswap_16, bswap_32, bswap_64 - reverse order of bytes
SYNOPSIS
#include <byteswap.h>
bswap_16(x);
bswap_32(x);
bswap_64(x);
DESCRIPTION
These macros return a value in which the order of the bytes in their 2-, 4-, or 8-byte arguments is reversed.
RETURN VALUE
These macros return the value of their argument with the bytes reversed.
ERRORS
These macros always succeed.
CONFORMING TO
These macros are GNU extensions.
EXAMPLE
The program below swaps the bytes of the 8-byte integer supplied as its command-line argument. The following shell session demonstrates
the use of the program:
$ ./a.out 0x0123456789abcdef
0x123456789abcdef ==> 0xefcdab8967452301
Program source
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <inttypes.h>
#include <byteswap.h>
int
main(int argc, char *argv[])
{
uint64_t x;
if (argc != 2) {
fprintf(stderr, "Usage: %s <num>
", argv[0]);
exit(EXIT_FAILURE);
}
x = strtoul(argv[1], NULL, 0);
printf("0x%" PRIx64 " ==> 0x%" PRIx64 "
", x, bswap_64(x));
exit(EXIT_SUCCESS);
}
SEE ALSO byteorder(3), endian(3)Linux 2019-03-06 BSWAP(3)