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Make the snippets sourceable.

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This commit is contained in:
Dylan Araps
2018-06-14 18:46:28 +10:00
parent 09ae875000
commit 8140a47dfb
1 changed files with 165 additions and 149 deletions
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96
README.md
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@@ -126,12 +126,14 @@ trim() {
### Split a string on a delimiter.
```sh
_() {
# To multiple variables.
string="1,2,3"
IFS=, read -r var1 var2 var3 <<< "$string"
# To an array.
IFS=, read -ra vars <<< "$string"
}
```
### Change a string to lowercase.
@@ -189,8 +191,8 @@ rstrip() {
### Assign and access a variable using a variable.
```sh
_() {
# First Example.
var1="world"
var2="hello_${var1}"
declare "${var2}=test_string"
@@ -198,7 +200,6 @@ printf '%s\n' "${!var2}"
# Second Example.
# Assign to a variable named after the
# value stored in '$var'.
var="test"
@@ -209,6 +210,7 @@ printf '%s\n' "set var \$$var to '${!var}'"
# Access the variable directly.
printf '%s\n' "set var \$$var to '$test'"
}
```
@@ -290,7 +292,9 @@ cycle() {
Alternative to the `cat` command.
```sh
_() {
file_data="$(<"file")"
}
```
### Read a file to an array (*by line*).
@@ -298,11 +302,13 @@ file_data="$(<"file")"
Alternative to the `cat` command.
```sh
_() {
# Bash <4
IFS=$'\n' read -d "" -ra file_data < "file"
# Bash 4+
mapfile -t file_data < "file"
}
```
### Get the first N lines of a file.
@@ -352,6 +358,7 @@ lines() {
Don’t use `ls`.
```sh
_() {
# Greedy example.
for file in *; do
printf '%s\n' "$file"
@@ -373,6 +380,7 @@ for file in ~/Pictures/**/*; do
printf '%s\n' "$file"
done
shopt -u globstar
}
```
### Count files or directories in directory.
@@ -393,11 +401,14 @@ count() {
Alternative to `touch`.
```sh
_() {
# Shortest.
:> file
# Longer alternatives:
echo -n > file
printf '' > file
}
```
## File Paths
@@ -430,6 +441,7 @@ basename() {
### Simpler syntax to set variables.
```sh
_() {
# Simple math
((var=1+2))
@@ -441,17 +453,20 @@ basename() {
# Using variables
((var=var2*arr[2]))
}
```
### Ternary tests.
```sh
_() {
# Set the value of var to var2 if var2 is greater than var.
# var: variable to set.
# var2>var: Condition to test.
# ?var2: If the test succeeds.
# :var: If the test fails.
((var=var2>var?var2:var))
}
```
## Colors
@@ -526,33 +541,38 @@ get_cursor_pos() {
### Shorter `for` loop syntax.
```sh
_() {
# Tiny C Style.
for((;i++<10;)){ echo "$i";}
# Undocumented method.
# Note: This is commented to make shellcheck play nice.
# for i in {1..10};{ echo "$i";}
for i in {1..10};{ echo "$i";}
# Expansion.
for i in {1..10}; do echo "$i"; done
# C Style.
for((i=0;i<=10;i++)); do echo "$i"; done
}
```
### Shorter infinite loops.
```sh
_() {
# Normal method
while :; do code; done
while :; do echo hi; done
# Shorter
for((;;)){ code;}
for((;;)){ echo hi;}
}
```
### Shorter function declaration.
```sh
_() {
# Normal method
f(){ echo hi;}
@@ -567,14 +587,15 @@ f()(($1))
# Using tests, loops etc.
# Note: You can also use ‘while’, ‘until’, ‘case’, ‘(())’, ‘[[]]’.
# Note: These are commented to make shellcheck play nice.
# f()if true; then echo "$1"; fi
# f()for i in "$@"; do echo "$i"; done
f()if true; then echo "$1"; fi
f()for i in "$@"; do echo "$i"; done
}
```
### Shorter `if` syntax.
```sh
_() {
# One line
[[ "$var" == hello ]] && echo hi || echo bye
[[ "$var" == hello ]] && { echo hi; echo there; } || echo bye
@@ -588,6 +609,7 @@ f()(($1))
echo hi
# ...
}
}
```
### Simpler `case` statement to set variable.
@@ -598,15 +620,9 @@ successful command. `:` always succeeds so we can abuse it to store the
variable value.
```sh
_() {
# Example snippet from Neofetch.
case "$(uname)" in
"SunOS"): "Solaris" ;;
"Haiku"): "Haiku" ;;
"MINIX"): "MINIX" ;;
"AIX"): "AIX" ;;
"IRIX"*): "IRIX" ;;
"FreeMiNT"): "FreeMiNT" ;;
"Linux" | "GNU"*)
: "Linux"
;;
@@ -620,14 +636,14 @@ case "$(uname)" in
;;
*)
printf '%s\n' "Unknown OS detected: '$kernel_name', aborting..." >&2
printf '%s\n' "Open an issue on GitHub to add support for your OS." >&2
printf '%s\n' "Unknown OS detected, aborting..." >&2
exit 1
;;
esac
# Finally, set the variable.
os="$_"
}
```
## Internal Variables
@@ -641,59 +657,59 @@ http://tldp.org/LDP/abs/html/internalvariables.html
### Get the location to the `bash` binary.
```sh
"$BASH"
: "$BASH"
```
### Get the version of the current running `bash` process.
```sh
# As a string.
"$BASH_VERSION"
: "$BASH_VERSION"
# As an array.
"${BASH_VERSINFO[@]}"
: "${BASH_VERSINFO[@]}"
```
### Open the user's preferred text editor.
```sh
"$EDITOR" "$file"
: "$EDITOR" "$file"
# NOTE: This variable may be empty, set a fallback value.
"${EDITOR:-vi}" "$file"
: "${EDITOR:-vi}" "$file"
```
### Get the name of the current function.
```sh
# Current function.
"${FUNCNAME[0]}"
: "${FUNCNAME[0]}"
# Parent function.
"${FUNCNAME[1]}"
: "${FUNCNAME[1]}"
# So on and so forth.
"${FUNCNAME[2]}"
"${FUNCNAME[3]}"
: "${FUNCNAME[2]}"
: "${FUNCNAME[3]}"
# All functions including parents.
"${FUNCNAME[@]}"
: "${FUNCNAME[@]}"
```
### Get the host-name of the system.
```sh
"$HOSTNAME"
: "$HOSTNAME"
# NOTE: This variable may be empty.
# Optionally set a fallback to the hostname command.
"${HOSTNAME:-$(hostname)}"
: "${HOSTNAME:-$(hostname)}"
```
### Get the architecture of the Operating System.
```sh
"$HOSTTYPE"
: "$HOSTTYPE"
```
### Get the name of the Operating System / Kernel.
@@ -702,7 +718,7 @@ This can be used to add conditional support for different Operating
Systems without needing to call `uname`.
```sh
"$OSTYPE"
: "$OSTYPE"
```
### Get the current working directory.
@@ -710,13 +726,13 @@ Systems without needing to call `uname`.
This is an alternative to the `pwd` built-in.
```sh
"$PWD"
: "$PWD"
```
### Get the number of seconds the script has been running.
```sh
"$SECONDS"
: "$SECONDS"
```
## Other
@@ -738,33 +754,33 @@ date() {
# Examples:
# Using date.
date "+%a %d %b - %l:%M %p"
: date "+%a %d %b - %l:%M %p"
# Using printf.
printf '%(%a %d %b - %l:%M %p)T\n' '-1'
: printf '%(%a %d %b - %l:%M %p)T\n' '-1'
# Assigning a variable.
printf -v date '%(%a %d %b - %l:%M %p)T\n' '-1'
: printf -v date '%(%a %d %b - %l:%M %p)T\n' '-1'
```
### Bypass shell aliases.
```sh
# alias
ls
: ls
# command
# shellcheck disable=SC1001
\ls
: \ls
```
### Bypass shell functions.
```sh
# function
ls
: ls
# command
command ls
: command ls
```