08-04-2009
Here's another detail that may help.
These two commands are equivalent:
head -5 file
head -n 5 file
So if you use -n $file_cnt instead of -$file_cnt the extra space would have no effect.
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
I am getting this message when I run my script.
$ runscript.sh
Not connected to any service!
Here is the beginning of the script:
# 1 - failure
#
# variable declaration
FILEDATE=`date +"%Y%m%d"`
Not connected to any service!
Right after the FILEDATE gets loaded I get that... (6 Replies)
Discussion started by: lesstjm
6 Replies
2. Programming
I have encountered a strange problem dealing with pipes
and forking. The program basicaly does this:
cat file | tbl | eqn | groff
Now, I have a parent process that forks children
that that exec the stuff that they should. The pipes defined
in the parent are the ones used.
The chain goes... (1 Reply)
Discussion started by: denoir
1 Replies
3. Solaris
Hi!
I own a sparc 5 and i seem to have a strange problem. When its off, it starts by itself...
Sounds a bit strange? Iknow. Does anyone know whats causing this?? Could it be the network card? or is it someting in ENV or some other configuration??
//dOzY (5 Replies)
Discussion started by: dozy
5 Replies
4. UNIX for Dummies Questions & Answers
Hi,
I have two machines, one is a E3500 and the other one is a V490;
I face a strange issue with both of them. The boot up sequence gives the output of the devalias command. Has anybody faced this?? Please do let me know what needs to be done o resolve this.
Regards,
NP (1 Reply)
Discussion started by: nitinp82
1 Replies
5. UNIX for Dummies Questions & Answers
I have Debian Etch release as a fresh install on a PIII to be a router/firewall. I've configured networking, and utilized Shorewall to set up iptables scripting. I've installed dhcp3, both client and server, to pull an ip from my broadband cable modem, and dish out ip's to a switch for other... (2 Replies)
Discussion started by: pflink
2 Replies
6. Shell Programming and Scripting
Hey, I'm trying to use awk for some simple file manipulations but i'm getting soem wierd results.
So i want to open up a file which looks like this:
@relation 'autoMpg'
@attribute a numeric
@attribute b numeric
@attribute c numeric
@data
-1.170815,0.257522,0.016416... (2 Replies)
Discussion started by: amatheny
2 Replies
7. AIX
Hello
It appears that on a regular basis, perhaps when weekly rebooting happens, not sure yet, my odm becomes out of sync.
When doing a smitty file system list by volume group, the FS type is displayed as ??? on several FSs. Always in the same VG.
I know how to fix this problem, thing is,... (4 Replies)
Discussion started by: mhenryj
4 Replies
8. Programming
Hi,
Please see this:
When i make a declaration as:
char *i, j, *k;
and then do
sprintf( k, "print.sh %s", i );
the program works fine.
But when i change the declaration to:
char *i, *k;
and then do
sprintf( k, "print.sh %s", i );
I get a segmentation fault at the 'sprintf'... (16 Replies)
Discussion started by: karthikb23
16 Replies
9. UNIX for Dummies Questions & Answers
I have a script that setsup the environmental variables and then goes on to ftp a file . The scripts which does is as follows
The script runs fine when i run it in my home dir and goes on to ftp the file..
But when the same file is run as a batch job in Control-M(a job scheduling software... (1 Reply)
Discussion started by: hareeshkumaru
1 Replies
10. Linux
I Have a COBOL application running over iscobol platform in Linux server.
we run Red Hat Enterprise Linux WS release 4 (Nahant Update 4)
Kernel \r on an \m
and the command "uname -a" gave me that:
Linux trilinux 2.6.9-42.ELsmp #1 SMP Wed Jul 12 23:27:17 EDT 2006 i686 i686 i386 GNU/Linux
... (1 Reply)
Discussion started by: TheReverend
1 Replies
LEARN ABOUT LINUX
set_robust_list
GET_ROBUST_LIST(2) Linux System Calls GET_ROBUST_LIST(2)
NAME
get_robust_list, set_robust_list - get/set list of robust futexes
SYNOPSIS
#include <linux/futex.h>
#include <sys/types.h>
#include <syscall.h>
long get_robust_list(int pid, struct robust_list_head **head_ptr,
size_t *len_ptr);
long set_robust_list(struct robust_list_head *head, size_t len);
Note: There are no glibc wrappers for these system calls; see NOTES.
DESCRIPTION
The robust futex implementation needs to maintain per-thread lists of robust futexes which are unlocked when the thread exits. These lists
are managed in user space; the kernel is notified about only the location of the head of the list.
The get_robust_list() system call returns the head of the robust futex list of the thread whose thread ID is specified in pid. If pid is
0, the head of the list for the calling thread is returned. The list head is stored in the location pointed to by head_ptr. The size of
the object pointed to by **head_ptr is stored in len_ptr.
The set_robust_list() system call requests the kernel to record the head of the list of robust futexes owned by the calling thread. The
head argument is the list head to record. The len argument should be sizeof(*head).
RETURN VALUE
The set_robust_list() and get_robust_list() system calls return zero when the operation is successful, an error code otherwise.
ERRORS
The set_robust_list() system call can fail with the following error:
EINVAL len does not match the size of structure struct robust_list_head expected by kernel.
The get_robust_list() system call can fail with the following errors:
EPERM The calling process does not have permission to see the robust futex list of the thread with the thread ID pid, and does not have
the CAP_SYS_PTRACE capability.
ESRCH No thread with the thread ID pid could be found.
EFAULT The head of the robust futex list can't be stored at the location head.
VERSIONS
These system calls were added in Linux 2.6.17.
NOTES
These system calls are not needed by normal applications. No support for them is provided in glibc. In the unlikely event that you want
to call them directly, use syscall(2).
A thread can have only one robust futex list; therefore applications that wish to use this functionality should use the robust mutexes pro-
vided by glibc.
SEE ALSO
futex(2)
Documentation/robust-futexes.txt and Documentation/robust-futex-ABI.txt in the Linux kernel source tree
Linux 2015-01-22 GET_ROBUST_LIST(2)