This is a cheat sheet for how to perform various actions to ZSH, which can be tricky to find on the web as the syntax is not intuitive and it is generally not very well-documented.
| Description | Syntax |
|---|---|
| Get the length of a string | ${#VARNAME} |
| Get a single character | ${VARNAME[index]} |
| Unicode table - List of most common Unicode characters * | |
| * This summary list contains about 2000 characters for most common ocidental/latin languages and most printable symbols but not chinese, japanese, arab, archaic and some unprintable. | |
| Contains character codes in HEX (hexadecimal), decimal number, name/description and corresponding printable symbol. | |
| What is Unicode? | |
| Unicode is a standard created to define letters of all languages and characters such as punctuation and technical symbols. Today, UNICODE (UTF-8) is the most used character set encoding (used by almost 70% of websites, in 2013). The second most used character set is ISO-8859-1 (about 20% of websites), but this old encoding format is being replaced by Unicode. | |
| How to identify the Unicode number for a character? | |
| Type or paste a character: |
| https://github.com/muan/unicode-emoji-json | |
| ° — degree | |
| × — times | |
| 💣 — bomb | |
| 💥 — explosion | |
| 🔥 — fire | |
| 🎉 — tada | |
| 🧯 — fire extinguisher |
| Latency Comparison Numbers | |
| -------------------------- | |
| L1 cache reference 0.5 ns | |
| Branch mispredict 5 ns | |
| L2 cache reference 7 ns 14x L1 cache | |
| Mutex lock/unlock 25 ns | |
| Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Zippy 3,000 ns 3 us | |
| Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
| Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |
