When you’re editing code in Vim and press Enter after a comment line, Vim automatically continues the comment on the next line. This is useful sometimes, but often gets in the way. Here’s how to disable it. The Basic Approach Add this to your ~/.vimrc: au FileType c,cpp setlocal comments-=:// comments+=f:// This works by: comments-=://…
LaTeX is a document preparation system widely used for scientific and technical documents. Most modern workflows use pdflatex or xelatex to compile directly to PDF, avoiding the outdated DVI → PostScript → PDF pipeline. Debian/Ubuntu sudo apt-get update sudo apt-get install texlive-latex-base texlive-latex-extra texlive-fonts-recommended For a complete installation with all packages: sudo apt-get install texlive-full…
GNOME Keyring stores encrypted credentials, SSH keys, and secrets for applications. If you need to disable it or start fresh after forgetting the password, you can remove the keyring database. Keyring Storage Locations The location of keyrings depends on your GNOME version and configuration: GNOME 3.0+: ~/.local/share/gnome-keyring/ or ~/.local/share/evolution/calendar/ Older GNOME: ~/.gnome2/keyrings/ XDG Base Directory…
iPhones have built-in emoji support that doesn’t require any third-party apps. The emoji keyboard is part of iOS and can be enabled directly through system settings. Enable the Emoji Keyboard Open Settings → General → Keyboard → Keyboards Tap Add New Keyboard Select Emoji from the list Tap Done Once enabled, you can switch to…
No-IP provides dynamic DNS service for systems that don’t have static IP addresses. The noip2 client daemon monitors your system’s IP and automatically updates your No-IP domain when changes occur. Here’s how to set it up properly. Prerequisites You’ll need: A No-IP account with at least one hostname configured Root or sudo access A Linux…
If you’re working with Microsoft Office 2007, converting documents to PDF or XPS format requires an additional add-in since native support wasn’t built into the original release. Installing the Save as PDF or XPS Add-in Microsoft provides a free add-in that enables PDF and XPS export across eight Office 2007 applications. Download it from Microsoft’s…
The error “Windows failed to start” with status code 0xc0000225 during Windows 7 64-bit installation on VirtualBox typically indicates a hardware abstraction layer (HAL) compatibility issue. This happens because the VM’s default configuration doesn’t properly expose interrupt controller details to the guest OS. Solution: Enable IO APIC The straightforward fix is to enable IO APIC…
By default, closing the last open tab closes the entire Chrome browser window. If you want Chrome to stay open and display a new tab instead, you’ll need to either use an extension or adjust your workflow. Using an Extension The Last Tab Standing extension is the most straightforward solution. It intercepts the close action…
To convert a PostScript file to PDF suitable for publishing, use ps2pdf from the Ghostscript suite: ps2pdf -dPDFSETTINGS=/printer file.ps file.pdf The /printer setting produces high-quality output appropriate for publication. Other available quality settings include: /screen — lowest quality, smallest file size /ebook — medium quality, reasonable file size /printer — high quality, suitable for printing…
Kernel parameters often need to be passed to Xen DomUs during boot or for troubleshooting. Common scenarios include booting into single-user mode for recovery, enabling kernel debugging, or adjusting memory/CPU settings at runtime. Using the extra parameter The simplest method is passing kernel parameters via the extra= option when creating or starting a DomU. For…
X11 forwarding over SSH lets you run graphical applications on remote systems and display them locally. Firefox is a common use case, though it requires careful configuration to avoid crashes and permission issues. Basic Setup The simplest approach uses X11 forwarding: ssh -X remotehost The -X flag enables trusted X11 forwarding. For untrusted forwarding (more…
When passwordless SSH authentication fails despite proper key setup, start by checking the SSH daemon logs to identify the actual problem. Checking SSH Logs The SSH daemon logs are your primary diagnostic tool: sudo tail -f /var/log/auth.log # Debian/Ubuntu sudo tail -f /var/log/secure # RHEL/CentOS/Fedora sudo journalctl -u ssh -f # systemd-based systems Watch the…
Keeping home directories synchronized across multiple machines is a practical problem for anyone managing several laptops, workstations, or servers. You need something that handles bidirectional sync, understands which changes win when conflicts occur, and doesn’t destroy data on either side. Unison Unison remains a solid choice for this. It’s a bidirectional file synchronizer that works…
IBus is the default input method framework on many Linux distributions, but Chrome and Chromium-based browsers have historically struggled with proper IBus integration. Other applications like Thunderbird, Firefox, and GNOME applications typically work fine, which points to Chrome’s specific handling of input methods. Root Causes Chrome doesn’t use the standard Linux input method pipeline that…
Dropbox on Linux has two main approaches: the official daemon (headless) or the sync client with GUI. Which you choose depends on your use case. Official Dropbox Daemon (Recommended for Servers) The daemon is lightweight and works well on headless systems. Download and extract it: cd ~ && wget -O – “https://www.dropbox.com/download?plat=lnx.x86_64” | tar xzf…
When working with relative paths in Linux, you often need the absolute path for scripting, logging, or passing to other programs. Several tools can resolve this, each with different strengths. Using readlink The readlink command is the traditional tool for this job. The -f flag follows symlinks and resolves the path to its absolute form:…
When you first use git on a machine, you’ll need to configure your identity. Git uses these credentials to author your commits: git config –global user.name “Your Name” git config –global user.email you@example.com These settings are stored in ~/.gitconfig and apply to all repositories on your system. Verifying your configuration Check what you’ve set: git…
The conventional wisdom that smaller code is always better has been thoroughly invalidated on modern processors. A statement from kernel development circles captured this well: for performance-critical paths like interrupt handlers, large-but-correctly-aligned-and-optimized code consistently outperforms byte-packed alternatives. Consider this comparison: mov eax, [foo] add eax, 1 mov [foo], eax versus: inc [foo] The three-instruction sequence…
Archiving or copying a 1TB sparse file containing only 32MB of actual data is impractical with naive approaches—you’ll waste time and I/O bandwidth copying zeros. The solution is using SEEK_HOLE and SEEK_DATA flags with lseek(), which allow tools to skip over hole regions entirely. How SEEK_HOLE and SEEK_DATA work The Linux kernel provides two additional…
If you suspect a disk has bad blocks, use the badblocks utility to scan for them. This tool probes a device (usually a disk partition) and reports which blocks are unreliable or unreadable. Basic Usage badblocks /dev/sda1 This scans /dev/sda1 from the first block to the last block on the device. Common Options -s: Show…