Bash trap Command Not Catching SIGINT or SIGTERM in Subshells
A trap handler that works correctly in the main script but doesn't fire inside a subshell or background process is expected Bash behavior — signal handling in...
Category
Linux / Bash
Solutions for permission errors, script failures, and common command-line troubleshooting on Linux.
Linux "Cannot Open Display" Running GUI App Over SSH or in Cron
"Cannot open display" means a GUI application needs an X11 display to render into, but none is available in the current context — an SSH session without X11...
Linux Memory Leak Analysis: free -m High "Used" Memory vs Cached/Buffers
High "used" memory reported by free -m is very often not a leak at all — Linux deliberately uses available RAM for disk caching and buffers to improve...
Linux "No Space Left on Device" Caused by Unlinked Deleted Files Holding Disk Space
When a Linux disk reports full despite deleted files, the space is very often still held by a long-running service — like journald, a database, or a web server...
Linux Process Stuck in D State (Uninterruptible Sleep), How to Handle
A process stuck in D state (uninterruptible sleep) is waiting on a kernel-level operation, typically I/O — and critically, it genuinely cannot be killed with a...
Linux Swap Space Full: How to Clear Swap Without Rebooting Server
Full swap space can be cleared without a reboot by temporarily disabling and re-enabling it — this forces the kernel to move any swapped-out data back into...
Linux systemctl Service Stuck in "activating (start-exec)" State
A service permanently stuck showing "activating (start-exec)" means systemd is waiting for the service's start process to signal that it's fully ready, but...
Bash Script Variable Lost Inside while read Loop Due to Pipe Subshell
A variable that appears correctly updated inside a while read loop, but reverts back to its original value the moment the loop finishes, is one of the most...
Bash Script xargs Failing on Filenames Containing Spaces or Special Characters
xargs failing on filenames with spaces isn't a bug — by default, both find's output and xargs's input parsing treat whitespace as a delimiter between separate...