writeToFile:atomically: what does atomically mean?

An 'atomic write' is one where you are guaranteed to have either a correct, complete write to the file or an error. There's no chance that, say, half of the write will work and then something bad happens (lost power, drive crash, etc) and the rest of the write fails. It's all or nothing. This is generally what you want.

atomically

If YES, the data is written to a backup file, and then—assuming no errors occur—the backup file is renamed to the name specified by path; otherwise, the data is written directly to path.

If $a+b+c+d=16$, then $(a+\frac{1}{c})^2+(c+\frac{1}{a})^2 + (b+\frac{1}{d})^2 + (d+\frac{1}{b})^2 \geq \frac{289}{4}$

A graded ring $R$ is graded-local iff $R_0$ is a local ring?

is the pushforward of a flat sheaf flat?

Finding singular points and computing dimension of tangent spaces (only for the brave)

Why is $10\frac{\exp(\pi)-\log 3}{\log 2}$ almost an integer?

Prevent firing focus event when clicking on div

A problem about a sequence and prime factorization

$K/E$, $E/F$ are separable field extensions $\implies$ $K/F $ is separable

Proving that there exists $a_i \in \{a_1,\dots,a_k\}$ so that for any positive integer $n$ $F(n)$ is divisible by $a_i$

What are the Eigenvectors of the curl operator?

Exercise 2.13, I. Martin Isaacs' Character Theory

Retrieving all rows of a table without HQL?