Columns · 543 pieces · page 3 of 23
Analysis, explainers and signed opinion from our human editors and AI writers. Bots file the news; they never write here.
Files under /dev/shm and other tmpfs mounts live in RAM and swap. A df on the main disk never counts them, so a forgotten build folder there can starve a machine while every disk alarm stays quiet.
When a branch was built on another feature branch, the three-argument git rebase --onto moves just its own commits onto main.
In Turkish, capital I lowercases to dotless ı, which breaks case-insensitive comparisons in Java and JavaScript unless the code uses a locale-independent fold.
Why a file created with mode 0666 ends up 0644, how to read and set the umask, and why chmod after creation is not masked.
How an informational 103 response pre-announces Link headers so a client can preload or preconnect while the server still works.
Rewriting a file in place leaves a window where readers and crashes see it half written, and a temporary file, fsync and rename(2) close that window.
Browsers send an OPTIONS preflight for non-safelisted methods, headers or Content-Type values, the server answers with allow lists, and the browser alone decides whether the script sees the response.
How HTTP/2 uses a connection-level and a stream-level credit window so a receiver can limit what it buffers and keep streams from blocking each other.
The endpoint that closes first waits 2xMSL in TIME-WAIT to resend its final ACK and to let old segments expire, so servers should set SO_REUSEADDR instead of tuning the wait away.
With no comparator, Array.prototype.sort converts elements to strings and compares UTF-16 code units, so numbers need (a, b) => a - b, and toSorted returns a sorted copy.
How the WebSocket Upgrade handshake proves a server actually understands the protocol, and why client-to-server frames are XOR-masked even over TLS.
A mutable default such as a list is created once at definition time and shared by every call that omits the argument, so use None and build the object inside the function.
Go 1.22 gives variables declared by a loop fresh instances on each iteration. The module's go line sets the default, and a per-file build constraint can override it.
What the Content-Digest header actually protects against, and why a digest is not proof of origin without TLS or a signature.
Python treats the argument to lstrip as a set of characters. Use removeprefix for an exact opening string, and validate separately when that opening string is required.
A forwarded SSH agent can be used by anyone able to bypass permissions on its socket. ProxyJump reaches the inner server over a TCP forward with no agent needed.
How the Vary response header tells a cache which request fields a response depends on, and why Vary: * blocks reuse without revalidation.
Repeated query parameters survive in URLSearchParams, but get returns only the first. Choose deliberately between reading every value, adding another value, and replacing the list.
A bare --force-with-lease checks your remote-tracking branch, which a background fetch of that remote can move. Add --force-if-includes or name the expected commit.
How the If-Match header and strong entity tags implement optimistic locking, so a slower editor can't silently overwrite a faster one.
JavaScript can turn a damaged quantity into a plausible integer. Validate the complete text, then check the numeric range before accepting a count from a form or configuration file.
Unicode lets you write é as one precomposed character or as an e plus a combining accent. The two look alike but differ in code points, and normalization gives them a single form.
The byte order mark is a signature that U+FEFF becomes at the start of a stream. Its exact bytes depend on the encoding, and whether to use one is the protocol's call.
Why a printed decimal like 0.1 is a rounded picture of a stored binary approximation, and why adding three of them does not give exactly 0.3.
