Add Generate A Sequence Of Numbered Items as a Unix TIL

unix/generate-a-sequence-of-numbered-items.md

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+# Generate A Sequence Of Numbered Items
+
+The `seq` command will output the specified sequence of numbers.
+
+```bash
+❯ seq 1 5
+1
+2
+3
+4
+5
+```
+
+With the `-f` (`--format`) flag we can interpolate those numbers as part of a
+string.
+
+```bash
+❯ seq -f "day_%02g" 1 5
+day_01
+day_02
+day_03
+day_04
+day_05
+```
+
+The `%g` indicates that there is a format specifier for a numeric type which is
+where `seq` will inject the current value in the sequence. The `02` indicates
+that it should be `0` padded to `2` digits.
+
+We can then pipe this to another unix command, such as `mkdir` in order to
+quickly create a bunch of directories for, say, [Advent of Code](https://adventofcode.com/2024).
+
+```bash
+❯ mkdir aoc_2024
+❯ cd aoc_2024
+❯ seq -f "day_%02g" 1 25 | xargs mkdir
+```
+
+See `man seq` for more details.