LaTeX Common Packages and Tips

The previous chapters have already used quite a few packages; this article systematically wraps up: package quick reference, custom commands, code typesetting, multi-file projects, latexmk, and troubleshooting techniques.

Master these "toolbox" topics, and you'll evolve from writing LaTeX to managing LaTeX projects.

Common Packages Quick Reference

Load packages with \usepackage[options]{package-name}, all placed in the preamble.

When the local environment prompts File 'xxx.sty' not found, use tlmgr install xxx to install (TeX Live); MiKTeX will automatically download. Overleaf comes with almost all packages, so no such trouble.

Custom Commands: \newcommand

When you've written the same content more than three times, it's time to define a command. \newcommand{\command-name}[number-of-parameters]{definition}.

Let's also learn the syntax for custom environments:

Code Typesetting: listings Package

To include code in technical documents, use the listings package; language highlighting, line numbers, and borders are all automatic.

lstlisting is a "verbatim environment": its contents are not interpreted by LaTeX at all, and & and % do not need escaping. The caption is also automatically numbered (Listing 1). Common language names include Python, C, Java, HTML, SQL, bash, etc. If language is not specified, it is colored as plain text.

listings' support for UTF-8 Chinese depends on the compiler: Chinese comments work normally under XeLaTeX; under legacy engines (latex/pdfLaTeX) they become garbled. For Chinese documents, always compile with XeLaTeX.

Multi-file Projects: \input and \include

When a document exceeds a few hundred lines, it should be split into files—main.tex acts only as the skeleton, and the content is divided and conquered.

The two commands look similar, but their behaviors are clearly divided.

Common pitfall: \include forces a page break. Using it to assemble "several sections on the same page" will cause unexpected page breaks—use \input for small fragments.

latexmk: One-click Compilation

The four-pass compilation pipeline from Chapter 9 is painful to type manually as four commands; latexmk handles it fully automatically.

$ latexmk -xelatex main.tex     # XeLaTeX 引擎编译，自动跑满所有遍数
$ latexmk -xelatex -c main.tex  # 清理中间文件（保留 PDF）
$ latexmk -xelatex -C main.tex  # 连 PDF 一起清理

latexmk automatically decides: if there is a .bib file, it runs bibtex; if cross-references change, it compiles several more times until all numbers are stable. Configuring the "build command" in your editor as latexmk is the best practice for a local environment.

Troubleshooting Techniques

LaTeX error messages start with an exclamation mark and include a line number, with a fixed format. Understanding the first few lines is enough.

! Undefined control sequence.
l.42 \secton{方法}

l.42 indicates the error line—in this example, line 42 misspelled \section as \secton. Fix this one spot, and a chain of subsequent errors often disappears together.

Always fix only the first error in the log—the later errors are mostly cascading effects of the first. After fixing, recompile; this is much more reliable than changing ten places at once.

Summary