First, there is the assignment of the filename variable.
Above, the first set the filename which was found from the ls command. See my echo of the variable. I then try to set to a file I know the ls will not find - and you can see the unix error condition returned. Tried agin; and I added the error handling. Note my second echo returns nothing.
Second, you are checking for -f or ordinary file. Is a zip file ordinary? I think I would be doing a -s to see if the file has non-zero length.
hi everyone
i have a problem in design as follows:
there is a structured file ,for example ,
field 1, field 2 .......
--------------
--------------
i read it into my memory ,there are some change in the memory
maybe add some record or change one field in an existing record.
i am going... (1 Reply)
Helo Experts,
I need a help in handling errors in shell script, wants my errors displayed in text file instead of command window..
My shell script is here;
cd /cygdrive/s/Files
for FILES in ./*.*
do
temp=`basename $FILES`
if cp $FILES /cygdrive/r/CopyFile1/$FILES; then
echo "copy... (5 Replies)
I have some unstable mistake in my program and out-of-idea how to catch it.
I am looking for advice with a way to work it out!
I have in a pretty complicated program (but one source file) set of int-counters - 15, if exactly.
Lately, on final printout I have inpossible value (I am... (3 Replies)
Hi All,
I have a CentOS operating system installed. I work with really huge number of files which are not only huge in number but some of them really huge in size. Minimum number of files could be 1 million to 2 million in one directory itself. Some of the files are even several Gigabytes in... (2 Replies)
Below code works for different databases i.e. MYSQL and ORACLE
The problem is for MYSQL in Block: if ; $? taking value accordingly but in case of ORACLE $? is always taking this value as zero (0).
That is the reason in Oracle it always going in else Block in any case.. :(
and in case of ... (4 Replies)
Hello fellow UNIX gurus :)
I have a problem regarding the script below:
# Variables used in this shell.
power=0 # Stores squared integer
total=0 # Sum of all squared integers
num=0 # Stores command line arguements
# Provides error handling if command line... (5 Replies)
HI All,
Whenever I write a shell script I always check if a command got executed successfully, even for the commands like cd, mv, rm and others, and even for the cases when there is ALMOST nothing to stop this commands from executing with success. so I am wondering if it is an overkill. I am... (1 Reply)
I am working on a shell script where after making sftp connection to a remote server the file are being transferred. The problem is how to capture return code for the file which is missing at the remote location. I have tried to capture the return code which return value of "0" even the transfer of... (4 Replies)
Hi Folks -
I want to add error handling to a portion of a *.ksh, but I'm having difficulty doing so in an easily digestible way.
Essentially, I want to echo weather it was successful or unsuccessful after each command.
Here is the code I need to add error handling to:
perl... (2 Replies)
Discussion started by: SIMMS7400
2 Replies
LEARN ABOUT X11R4
posix_madvise
POSIX_MADVISE(3) Linux Programmer's Manual POSIX_MADVISE(3)NAME
posix_madvise - give advice about patterns of memory usage
SYNOPSIS
#include <sys/mman.h>
int posix_madvise(void *addr, size_t len, int advice);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
posix_madvise():
_POSIX_C_SOURCE >= 200112L
DESCRIPTION
The posix_madvise() function allows an application to advise the system about its expected patterns of usage of memory in the address range
starting at addr and continuing for len bytes. The system is free to use this advice in order to improve the performance of memory
accesses (or to ignore the advice altogether), but calling posix_madvise() shall not affect the semantics of access to memory in the speci-
fied range.
The advice argument is one of the following:
POSIX_MADV_NORMAL
The application has no special advice regarding its memory usage patterns for the specified address range. This is the default
behavior.
POSIX_MADV_SEQUENTIAL
The application expects to access the specified address range sequentially, running from lower addresses to higher addresses.
Hence, pages in this region can be aggressively read ahead, and may be freed soon after they are accessed.
POSIX_MADV_RANDOM
The application expects to access the specified address range randomly. Thus, read ahead may be less useful than normally.
POSIX_MADV_WILLNEED
The application expects to access the specified address range in the near future. Thus, read ahead may be beneficial.
POSIX_MADV_DONTNEED
The application expects that it will not access the specified address range in the near future.
RETURN VALUE
On success, posix_madvise() returns 0. On failure, it returns a positive error number.
ERRORS
EINVAL addr is not a multiple of the system page size or len is negative.
EINVAL advice is invalid.
ENOMEM Addresses in the specified range are partially or completely outside the caller's address space.
VERSIONS
Support for posix_madvise() first appeared in glibc version 2.2.
CONFORMING TO
POSIX.1-2001.
NOTES
POSIX.1 permits an implementation to generate an error if len is 0. On Linux, specifying len as 0 is permitted (as a successful no-op).
In glibc, this function is implemented using madvise(2). However, since glibc 2.6, POSIX_MADV_DONTNEED is treated as a no-op, because the
corresponding madvise(2) value, MADV_DONTNEED, has destructive semantics.
SEE ALSO madvise(2), posix_fadvise(2)COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the
latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
Linux 2017-09-15 POSIX_MADVISE(3)