linux Errors

5 error patterns

Permission Denied

Permission denied|EACCES|Operation not permitted

•Check file permissions with `ls -la` — fix with `chmod 644 file` or `chmod 755 dir`
•Run with `sudo` if root access is required, or change file ownership with `chown user:group file`

Command Not Found

command not found|not recognized as.*command

•Install the missing package: `apt install <package>` or `yum install <package>`
•Check if the binary is in your PATH: `echo $PATH` — add it with `export PATH=$PATH:/new/path`

No Space Left on Device

No space left on device|ENOSPC|disk full

•Find large files: `du -sh /* | sort -rh | head -20` and clean up logs, temp files, or old Docker images
•Clear package cache: `apt clean` or `docker system prune -a` to reclaim space

Too Many Open Files

Too many open files|EMFILE|ulimit

•Increase the limit: `ulimit -n 65536` for the current session
•Permanently increase in `/etc/security/limits.conf`: `* soft nofile 65536` and `* hard nofile 65536`

Segmentation Fault (Core Dumped)

Segmentation fault|segfault|SIGSEGV|core dumped

•Enable core dumps (`ulimit -c unlimited`) and analyze with `gdb ./program core` to find the crash location
•Run with AddressSanitizer: compile with `-fsanitize=address` to detect memory errors