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Dylan Araps
2018-06-13 14:23:18 +10:00
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README.md
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@@ -24,14 +24,6 @@ scripts and not full blown utilities.
<!-- vim-markdown-toc GFM -->
* [File handling](#file-handling)
* [Read a file to a string.](#read-a-file-to-a-string)
* [Read a file to an array (*by line*).](#read-a-file-to-an-array-by-line)
* [Get the first N lines of a file.](#get-the-first-n-lines-of-a-file)
* [Get the last N lines of a file.](#get-the-last-n-lines-of-a-file)
* [Get the number of lines in a file.](#get-the-number-of-lines-in-a-file)
* [Iterate over files.](#iterate-over-files)
* [Create an empty file.](#create-an-empty-file)
* [Strings](#strings)
* [Trim white-space from string.](#trim-white-space-from-string)
* [Split a string on a delimiter.](#split-a-string-on-a-delimiter)
@@ -42,13 +34,22 @@ scripts and not full blown utilities.
* [Strip characters from end of string.](#strip-characters-from-end-of-string)
* [Arrays](#arrays)
* [Reverse an array.](#reverse-an-array)
* [File handling](#file-handling)
* [Read a file to a string.](#read-a-file-to-a-string)
* [Read a file to an array (*by line*).](#read-a-file-to-an-array-by-line)
* [Get the first N lines of a file.](#get-the-first-n-lines-of-a-file)
* [Get the last N lines of a file.](#get-the-last-n-lines-of-a-file)
* [Get the number of lines in a file.](#get-the-number-of-lines-in-a-file)
* [Iterate over files.](#iterate-over-files)
* [Count files or directories in directory.](#count-files-or-directories-in-directory)
* [Create an empty file.](#create-an-empty-file)
* [File Paths](#file-paths)
* [Get the directory name of a file path.](#get-the-directory-name-of-a-file-path)
* [Get the base-name of a file path.](#get-the-base-name-of-a-file-path)
* [Colors](#colors)
* [Convert a hex color to RGB.](#convert-a-hex-color-to-rgb)
* [Convert an RGB color to hex.](#convert-an-rgb-color-to-hex)
* [Information about the terminal.](#information-about-the-terminal)
* [Information about the terminal](#information-about-the-terminal)
* [Get the terminal size in lines and columns (*from a script*).](#get-the-terminal-size-in-lines-and-columns-from-a-script)
* [Get the terminal size in pixels.](#get-the-terminal-size-in-pixels)
* [Get the current cursor position.](#get-the-current-cursor-position)
@@ -57,108 +58,6 @@ scripts and not full blown utilities.
<!-- vim-markdown-toc -->
## File handling
### Read a file to a string.
Alternative to the `cat` command.
```sh
file_data="$(<"file")"
```
### Read a file to an array (*by line*).
Alternative to the `cat` command.
```sh
IFS=$'\n' read -d "" -ra file_data < "file"
```
### Get the first N lines of a file.
Alternative to the `head` command.
**NOTE:** Requires `bash` 4+
```sh
head() {
# Usage: head "n" "file"
mapfile -tn "$1" line < "$2"
printf '%s\n' "${line[@]}"
}
```
### Get the last N lines of a file.
Alternative to the `tail` command.
**NOTE:** Requires `bash` 4+
```sh
tail() {
# Usage: tail "n" "file"
mapfile -tn 0 line < "$2"
printf '%s\n' "${line[@]: -$1}"
}
```
### Get the number of lines in a file.
Alternative to `wc -l`.
**NOTE:** Requires `bash` 4+
```sh
lines() {
# Usage lines "file"
mapfile -tn 0 lines < "$1"
printf '%s\n' "${#lines[@]}"
}
```
### Iterate over files.
Don’t use `ls`.
```sh
# Greedy example.
for file in *; do
echo "$file"
done
# PNG files in dir.
for file in ~/Pictures/*.png; do
echo "$file"
done
# Iterate over directories.
for dir in ~/Downloads/; do
echo "$dir"
done
# Iterate recursively.
shopt -s globstar
for file in ~/Pictures/**/*; do
echo "$file"
done
shopt -u globstar
```
### Create an empty file.
Alternative to `touch`.
```sh
:> file
# Longer alternatives:
echo -n > file
printf '' > file
```
## Strings
@@ -257,6 +156,120 @@ reverse_array() {
}
```
## File handling
### Read a file to a string.
Alternative to the `cat` command.
```sh
file_data="$(<"file")"
```
### Read a file to an array (*by line*).
Alternative to the `cat` command.
```sh
IFS=$'\n' read -d "" -ra file_data < "file"
```
### Get the first N lines of a file.
Alternative to the `head` command.
**NOTE:** Requires `bash` 4+
```sh
head() {
# Usage: head "n" "file"
mapfile -tn "$1" line < "$2"
printf '%s\n' "${line[@]}"
}
```
### Get the last N lines of a file.
Alternative to the `tail` command.
**NOTE:** Requires `bash` 4+
```sh
tail() {
# Usage: tail "n" "file"
mapfile -tn 0 line < "$2"
printf '%s\n' "${line[@]: -$1}"
}
```
### Get the number of lines in a file.
Alternative to `wc -l`.
**NOTE:** Requires `bash` 4+
```sh
lines() {
# Usage lines "file"
mapfile -tn 0 lines < "$1"
printf '%s\n' "${#lines[@]}"
}
```
### Iterate over files.
Don’t use `ls`.
```sh
# Greedy example.
for file in *; do
echo "$file"
done
# PNG files in dir.
for file in ~/Pictures/*.png; do
echo "$file"
done
# Iterate over directories.
for dir in ~/Downloads/; do
echo "$dir"
done
# Iterate recursively.
shopt -s globstar
for file in ~/Pictures/**/*; do
echo "$file"
done
shopt -u globstar
```
### Count files or directories in directory.
This works by passing the output of the glob as function arguments. We
then count the arguments and print the number.
```sh
count() {
# Usage: count /path/to/dir/*
# count /path/to/dir/*/
printf '%s\n' "$#"
}
```
### Create an empty file.
Alternative to `touch`.
```sh
:> file
# Longer alternatives:
echo -n > file
printf '' > file
```
## File Paths
### Get the directory name of a file path.
@@ -282,7 +295,6 @@ basename() {
}
```
## Colors
### Convert a hex color to RGB.
@@ -307,7 +319,7 @@ rgb_to_hex() {
}
```
## Information about the terminal.
## Information about the terminal
### Get the terminal size in lines and columns (*from a script*).