The previous chapter introduced the three standard streams and the operators that control them. This chapter goes deeper into the output redirection specifically: the >, the >>, the 2>, the 2>>, the &>, the &>>, and the 2>&1 that ties them together. The output redirection is the mechanism that captures the output of a command…
Every process on a Linux system is born with three open file descriptors. File descriptor 0 is standard input (stdin), the channel the process reads from. File descriptor 1 is standard output (stdout), the channel the process writes its normal results to. File descriptor 2 is standard error (stderr), the channel the process writes its…
The earlier chapter introduced grep as a line-oriented filter. This chapter goes deeper. The basic options — -i, -v, -c, -n, -l, -q, -r — are the foundation, but the real power of grep is in the regular expressions and the options that control the matching, the output, and the file selection. The LFCS exam…
find is the most powerful file-searching tool on Linux. It walks a directory tree, evaluates an expression against each file, and prints or acts on the files that match. Unlike locate, which searches a pre-built database, find searches the actual file system in real time, so it always reflects the current state. Unlike ls with…
The compression landscape has shifted. For two decades, gzip and bzip2 were the standard tools, and xz was the heavy hitter for maximum ratio. But the modern workloads demand something different: compression that is fast enough for real-time data, for container images, for log streams, and for the kernel’s own initramfs. The two algorithms that…
A component’s content is not always a single block. A layout component has a header, a body, and a footer. A card has a title, an image, and a description. A modal has a header, a body, and the action buttons. The default slot receives one block of content, and the component decides where it…
A component’s template defines its structure, but not all of its content. A button defines the <button> element, but the text inside comes from the parent. A card defines the border, the shadow, and the padding, but the content — the title, the body, the footer — comes from the parent. The <slot> element is…
A component often needs more than one two-way binding. A form component has a first name and a last name. A date-range picker has a start date and an end date. A filter panel has a search term and a category. A settings component has a theme and a language. Each of these is a…
Two-way binding is the pattern where a value flows from the parent to the child as a prop, and the child’s changes flow back to the parent as an event. In Vue, the v-model directive is the syntactic sugar for this pattern. On a native input, v-model=”name” expands to :value=”name” and @input=”name = $event.target.value”. On…
A component’s root element receives the attributes that the parent passes to the component but that the component does not declare as props. This is attribute fallthrough, and it is the default behavior in Vue 3. A parent writes <MyButton class=”btn” id=”submit” @click=”handleClick” />, and the class, the id, and the @click listener are all…