That seems an awkward thing to do in shell. It'd also make it difficult to run two instances of sleep. I'd write it in C:
Run it and hit ctrl-C, and it will show a prompt telling you how much is left then ask for an offset in seconds. A positive number of seconds will add time, a negative number will subtract time. It calculates all this time relative to the program start, so a 'resleep 90', ctrl-c, then adding 25 will have it end precisely 115 seconds after it started even though some seconds may have been spent waiting for you to type. If you hit ctrl-C again instead of entering an offset, it just quits.
Last edited by Corona688; 09-25-2009 at 06:49 PM..
If I want a script to sleep for less than a second, would I use a decimal? In other words, if I wanted my script to sleep for 1/4 of a second, would I say, SLEEP .25 ?? (5 Replies)
Does anyone know a way to sleep less than 1 second?
Sometimes when I write scripts that iterates a loop many times it would be
nice to slow things down, but sometimes 1 second is too much. (9 Replies)
Hey everyone, just entering the linux world, I need some help with a shell script i'm trying to write, the purpose is to check every 10 minutes what was the last time a certain file was modified, and if there is a connection to the server at this moment send an email with the date of the... (2 Replies)
This is the gdb backtrace.
^C
Program received signal SIGINT, Interrupt.
0xffffe424 in __kernel_vsyscall ()
(gdb) bt
#0 0xffffe424 in __kernel_vsyscall ()
#1 0xb7e56a70 in __nanosleep_nocancel () from /lib/libc.so.6
#2 0xb7e568bb in __sleep (seconds=0) at sleep.c:138
#3 0x080496d5 in... (6 Replies)
Hi All,
I am new to Unix , there i am facing one problem with sleep command. that is ..
in while loop i have defined sleep function ..
my condition is like this
while #i knew this is infinite loop
do
sleep 200
echo "hello "
done.
this condition will never become .. true... (3 Replies)
Hi,
I have a script that runs a process at the beginning and I want to sleep/wait until this process is finished and then continue with the rest of the script. I am trying with this, but it is not working:
process=`ps -ef | grep "proc_p01 -c" | grep -v grep | wc -l`
if ; do
sleep 10
done... (7 Replies)
Hello Im using geany to write my c codes. Below is my code to make the internal LED of beaglebone flashing. But i cant seem to use the sleep or delay to make the program wait for a couple of miliseconds. I've included all include files that i can find but none of it solve the problem. Any help is... (1 Reply)
Hi , I have a doubt with signals and sleep function.
In a program i have this
while(1)
{
//do some work
sleep(1);
}And in a thread i have something like this
union sigval data;
char message;
char msg;
data.sival_int=0;
while(1)
{
... (4 Replies)
Discussion started by: bacesado
4 Replies
LEARN ABOUT DEBIAN
tee
TEE(2) Linux Programmer's Manual TEE(2)NAME
tee - duplicating pipe content
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <fcntl.h>
ssize_t tee(int fd_in, int fd_out, size_t len, unsigned int flags);
DESCRIPTION
tee() duplicates up to len bytes of data from the pipe referred to by the file descriptor fd_in to the pipe referred to by the file
descriptor fd_out. It does not consume the data that is duplicated from fd_in; therefore, that data can be copied by a subsequent
splice(2).
flags is a series of modifier flags, which share the name space with splice(2) and vmsplice(2):
SPLICE_F_MOVE Currently has no effect for tee(); see splice(2).
SPLICE_F_NONBLOCK Do not block on I/O; see splice(2) for further details.
SPLICE_F_MORE Currently has no effect for tee(), but may be implemented in the future; see splice(2).
SPLICE_F_GIFT Unused for tee(); see vmsplice(2).
RETURN VALUE
Upon successful completion, tee() returns the number of bytes that were duplicated between the input and output. A return value of 0 means
that there was no data to transfer, and it would not make sense to block, because there are no writers connected to the write end of the
pipe referred to by fd_in.
On error, tee() returns -1 and errno is set to indicate the error.
ERRORS
EINVAL fd_in or fd_out does not refer to a pipe; or fd_in and fd_out refer to the same pipe.
ENOMEM Out of memory.
VERSIONS
The tee() system call first appeared in Linux 2.6.17; library support was added to glibc in version 2.5.
CONFORMING TO
This system call is Linux-specific.
NOTES
Conceptually, tee() copies the data between the two pipes. In reality no real data copying takes place though: under the covers, tee()
assigns data in the output by merely grabbing a reference to the input.
EXAMPLE
The following example implements a basic tee(1) program using the tee() system call.
#define _GNU_SOURCE
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <limits.h>
int
main(int argc, char *argv[])
{
int fd;
int len, slen;
if (argc != 2) {
fprintf(stderr, "Usage: %s <file>
", argv[0]);
exit(EXIT_FAILURE);
}
fd = open(argv[1], O_WRONLY | O_CREAT | O_TRUNC, 0644);
if (fd == -1) {
perror("open");
exit(EXIT_FAILURE);
}
do {
/*
* tee stdin to stdout.
*/
len = tee(STDIN_FILENO, STDOUT_FILENO,
INT_MAX, SPLICE_F_NONBLOCK);
if (len < 0) {
if (errno == EAGAIN)
continue;
perror("tee");
exit(EXIT_FAILURE);
} else
if (len == 0)
break;
/*
* Consume stdin by splicing it to a file.
*/
while (len > 0) {
slen = splice(STDIN_FILENO, NULL, fd, NULL,
len, SPLICE_F_MOVE);
if (slen < 0) {
perror("splice");
break;
}
len -= slen;
}
} while (1);
close(fd);
exit(EXIT_SUCCESS);
}
SEE ALSO splice(2), vmsplice(2)COLOPHON
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2012-05-04 TEE(2)