9 More Discussions You Might Find Interesting
1. Red Hat
Hello All,
I am new joiner of this forum.I am new to Linux shell scripting.
At present I have identified 1 application which stalls very frequently (PID is say xyz) and I am not having much information in its application log to identify the root cause of stalling. I need to take the core dump... (19 Replies)
Discussion started by: Anjan Ganguly
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2. UNIX for Dummies Questions & Answers
I have come into a business environtment problem and had been 10+ years since the last time I did any unix admin work.
A long time ago some mainframe person created an app that talked to a mainframe on UNIX and wrote a c program with "core" in the file name to indicate that the file was the... (2 Replies)
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3. Linux
Hi everybody,
I want to find out all the processes that ran before a server crashed. Is that possible?
I've looked in /var/log/messages and found out that the system was out of memory.
A user probably wrote a script (in Perl or Python) that used up all available memory and crashed the... (11 Replies)
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4. AIX
Hi ,
I want to read core dump file on AIX5.3. While i am trying to use following commands, i am getting only few lines of information.
ux201p3:e46123> dbx capsWrkstnMgr core
Type 'help' for help.
reading symbolic information ...
Segmentation fault in malloc_common.extend_brk at... (1 Reply)
Discussion started by: rps
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5. UNIX for Dummies Questions & Answers
We have an application that terminates with segmentation violation errors in the logs. No source code is available since this is a third party software that is way past its maintenance life cycle. Under these circumstances is there a way to force a core dump of the process for further analysis??
... (3 Replies)
Discussion started by: Un1xNewb1e
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6. UNIX for Dummies Questions & Answers
Hi All
I am new for this forum. I have a core file by using gdb and bt cmd I got the function name but I want to the exact cause of the core dump because of I can not reproduse the binary so if any one know the cmd plz plz plz let me know. (0 Replies)
Discussion started by: gyanusoni
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7. Shell Programming and Scripting
Hello,
I host a couple of Call of Duty gameing servers. There are some hackers who love the crash them. When they crash them it simply causes a segmentaion fault and kills the PID. I was wondering it you could help me write a script to simply restart the program after it has been crashed. The... (9 Replies)
Discussion started by: Phobos
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8. Programming
MY friends:
my program under sco unix have a problem?
it create a core dump file on the path when execute program ,
but i can't find the error of the C program ,i don't know how to
see the error about my program use core, please help me
or give me some suggest and what tools can use... (1 Reply)
Discussion started by: zhaohaizhou
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9. UNIX for Dummies Questions & Answers
help, what is the difference between core dump and panic dump? (1 Reply)
Discussion started by: aileen
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limit(1) limit(1)
NAME
limit, ulimit, unlimit - set or get limitations on the system resources available to the current shell and its descendents
SYNOPSIS
/usr/bin/ulimit [-f] [blocks]
sh
ulimit [ - [HS] [ a | cdfnstv]]
ulimit [ - [HS] [ c | d | f | n | s | t | v]] limit
csh
limit [-h] [ resource [limit]]
unlimit [-h] [resource]
ksh
ulimit [-HSacdfnstv] [limit]
/usr/bin/ulimit
The ulimit utility sets or reports the file-size writing limit imposed on files written by the shell and its child processes (files of any
size may be read). Only a process with appropriate privileges can increase the limit.
sh
The Bourne shell built-in function, ulimit, prints or sets hard or soft resource limits. These limits are described in getrlimit(2).
If limit is not present, ulimit prints the specified limits. Any number of limits may be printed at one time. The -a option prints all lim-
its.
If limit is present, ulimit sets the specified limit to limit. The string unlimited requests the largest valid limit. Limits may be set for
only one resource at a time. Any user may set a soft limit to any value below the hard limit. Any user may lower a hard limit. Only a
super-user may raise a hard limit. See su(1M).
The -H option specifies a hard limit. The -S option specifies a soft limit. If neither option is specified, ulimit will set both limits and
print the soft limit.
The following options specify the resource whose limits are to be printed or set. If no option is specified, the file size limit is printed
or set.
-c maximum core file size (in 512-byte blocks)
-d maximum size of data segment or heap (in kbytes)
-f maximum file size (in 512-byte blocks)
-n maximum file descriptor plus 1
-s maximum size of stack segment (in kbytes)
-t maximum CPU time (in seconds)
-v maximum size of virtual memory (in kbytes)
csh
The C-shell built-in function, limit, limits the consumption by the current process or any process it spawns, each not to exceed limit on
the specified resource. If limit is omitted, print the current limit; if resource is omitted, display all limits.
-h Use hard limits instead of the current limits. Hard limits impose a ceiling on the values of the current limits. Only the privi-
leged user may raise the hard limits.
resource is one of:
cputime Maximum CPU seconds per process.
filesize Largest single file allowed. Limited to the size of the filesystem (see df(1M)).
datasize The maximum size of a process's heap in kilobytes.
stacksize Maximum stack size for the process. The default stack size is 2**64.
coredumpsize Maximum size of a core dump (file). This is limited to the size of the filesystem.
descriptors Maximum number of file descriptors. Run the sysdef(1M) command to obtain the maximum possible limits for your system. The
values reported are in hexadecimal, but can be translated into decimal numbers using the bc(1) command.
memorysize Maximum size of virtual memory.
limit is a number, with an optional scaling factor, as follows:
nh Hours (for cputime).
nk n kilobytes. This is the default for all but cputime.
nm n megabytes or minutes (for cputime).
mm:ss Minutes and seconds (for cputime).
unlimit removes a limitation on resource. If no resource is specified, then all resource limitations are removed. See the description of
the limit command for the list of resource names.
-h Remove corresponding hard limits. Only the privileged user may do this.
ksh
The Korn shell built-in function, ulimit, sets or displays a resource limit. The available resources limits are listed below. Many systems
do not contain one or more of these limits. The limit for a specified resource is set when limit is specified. The value of limit can be a
number in the unit specified below with each resource, or the value unlimited. The -H and -S flags specify whether the hard limit or the
soft limit for the given resource is set. A hard limit cannot be increased once it is set. A soft limit can be increased up to the value of
the hard limit. If neither the -H or -S options is specified, the limit applies to both. The current resource limit is printed when limit
is omitted. In this case, the soft limit is printed unless -H is specified. When more than one resource is specified, then the limit name
and unit is printed before the value.
-a Lists all of the current resource limits.
-c The number of 512-byte blocks on the size of core dumps.
-d The number of K-bytes on the size of the data area.
-f The number of 512-byte blocks on files written by child processes (files of any size may be read).
-n The number of file descriptors plus 1.
-s The number of K-bytes on the size of the stack area.
-t The number of seconds (CPU time) to be used by each process.
-v The number of K-bytes for virtual memory.
If no option is given, -f is assumed.
Per-Shell Memory Parameters
The heapsize, datasize, and stacksize parameters are not system tunables. The only controls for these are hard limits, set in a shell
startup file, or system-wide soft limits, which, for the current version of the Solaris OS, is 2**64bytes.
The following option is supported by ulimit:
-f Sets (or reports, if no blocks operand is present), the file size limit in blocks. The -f option is also the default case.
The following operand is supported by ulimit:
blocks The number of 512-byte blocks to use as the new file size limit.
/usr/bin/ulimit
Example 1: Limiting the Stack Size
The following example limits the stack size to 512 kilobytes:
example% ulimit -s 512
example% ulimit -a
time(seconds) unlimited
file(blocks) 100
data(kbytes) 523256
stack(kbytes) 512
coredump(blocks) 200
nofiles(descriptors) 64
memory(kbytes) unlimited
sh/ksh
Example 2: Limiting the Number of File Descriptors
The following command limits the number of file descriptors to 12:
example$ ulimit -n 12
example$ ulimit -a
time(seconds) unlimited
file(blocks) 41943
data(kbytes) 523256
stack(kbytes) 8192
coredump(blocks) 200
nofiles(descriptors) 12
vmemory(kbytes) unlimited
csh
Example 3: Limiting the Core Dump File Size
The following command limits the size of a core dump file size to 0 kilobytes:
example% limit coredumpsize 0
example% limit
cputime unlimited
filesize unlimited
datasize 523256 kbytes
stacksize 8192 kbytes
coredumpsize 0 kbytes
descriptors 64
memorysize unlimited
Example 4: Removing the limitation for core file size
The following command removes the above limitation for the core file size:
example% unlimit coredumpsize
example% limit
cputime unlimited
filesize unlimited
datasize 523256 kbytes
stacksize 8192 kbytes
coredumpsize unlimited
descriptors 64
memorysize unlimited
See environ(5) for descriptions of the following environment variables that affect the execution of ulimit: LANG, LC_ALL, LC_CTYPE, LC_MES-
SAGES, and NLSPATH.
The following exit values are returned by ulimit:
0 Successful completion.
>0 A request for a higher limit was rejected or an error occurred.
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
bc(1), csh(1), ksh(1), sh(1), df(1M), su(1M), swap(1M), sysdef(1M), getrlimit(2), attributes(5), environ(5), standards(5)
19 Aug 2005 limit(1)