Questions tagged [posix]
POSIX (Portable Operating System Interface) is a set of standards defining programming APIs, a command interpreter, and common utilities for Unix-like operating systems.
posix
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Can pthread_cond_wait() be called with read-write lock?
I know pthread_cond_wait() shall be used with mutex, but I'm curious if it can be used with rwlock.
I read manual page of pthread_cond_wait() and it didn't say anything about using read-write lock, ...
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Attempting to write to disk and check the before and after availability of space using statvfs, but I see no change in blocks available
I am using statvfs to monitor my disk space. I run this program and see no changes in the amount of available blocks within my system, but when I run the df command I am able to see that there's disk ...
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negative value in __writer member variable of struct pthread_rwlock_t [closed]
I am debugging one deadlock case in my application running on RHEL 7(glibc 2.17). When inspecting using gdb, at the time of deadlock, I see the following values on printing std::shared_timed_mutex(...
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Reading and writing the same file with different file handles
I apologize if this is a duplicate question.
OS/Language:
C++ 11/14
Linux (Rocky 4.18.0-425.3.1.el8.x86_64)
libc.so.6
Use Case:
Application has two threads, one writes ~7K data (text appended with a ...
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3
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sed - Posix compliant generic multiple insert/appends single command
I'd like to perform multiple inserts/appends in a single sed command that is portable.
In GNU sed, I can do something like:
sed -e '1i hi' -e '$a bye' <(seq 1 10)
I've the found the following works,...
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Repeated short identical parallel jobs
I have an algorithm that requires many parallel reruns of the same code. The code is short and finishes in less than a microsecond. This will be run millions of times which creates some problems when ...
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Where should a binary file that must be executed by another program be stored on a UNIX system?
I am writing a program that uses a library which requires that my program be called by a driver which initializes the environment etc first. This is done by passing the path of my executable (or just ...
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Problem with malloc and shared memory in C
I am trying to put shared_pid_data in shared memory. I need to have a dynamic array, so I use malloc, I also tried using calloc getting the same result. The problem I am encountering is that the data ...
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File created with fmemopen has no contents after writing
I have some files on disk that I want to read in and concatenate. I don't want to create a new temporary file on disk. So I decided to use fmemopen to read/write to memory and access it using FILE ...
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comparison operator syntax in posix shell
I'm trying to understand the grammar/syntax of the shell command language (to be able to parse it) and I cannot seem to find where the syntax of the comparison operations is defined.
As an example:
x=...
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POSIX or Linux-specific method of connecting a readable file descriptor to a writable file descriptor?
I've got a file descriptor, which might've come from a socket, a pipe, or an actual file, that can be read from. I've got another file descriptor (again, might represent a socket or an actual file) ...
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3
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53
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How can you force a blocked mq_receive call to give up?
I am trying to upgrade a messaging library from SYSV message queues to POSIX message queues. Unlike with SYSV queues, closing and/or deleting a POSIX message queue that is blocked in mq_receive() ...
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Process synchronisation for different processes not working with 2 semaphores [duplicate]
I am trying to learn process synchronization , I am trying semaphore,to print odd and even numbers alternatively using 2 processes , one process will execute odd function and another process will ...
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For wrappers around syscalls that retry on EINTR, how many times does retrying make sense?
Often syscalls like write(2), read(2), close(2) et cetera fail due to being interrupted by a signal with the errno value EINTR (say the size of the terminal window changed and SIGWINCH was received), ...
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Posix Timer timer is not accurate
I'm working on vxWorks 7. I've developed a class to implement POSIX timer. I'm working on a Real Time Process.
The timer is designed to run in single-shot or periodic mode.
The problem is I'm getting ...
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