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bash-snippets

Here's some reusable bash code and tools I've written with the primary goal of simplicity and ease of use.

If not specified otherwise, download the individual files and they will work without any additional dependencies.

source dst/strings.sh

if strings_end_with "$s" "$end";then
    echo "yes, '$s' end with '$end'"
fi

• layout
• result
• declaration
• test.sh
• api

layout

• dst This folder contains all reusable code repositories
• example This folder contains some usage examples
• src Some code generated from source in src
• generate.sh Executing this script regenerates the archive created by the code
• test.sh A bash unit testing tool

result

The bash function cannot return anything other than an integer. The solution is to use a global variable to return, or use echo return string. This library uses global variables to return content for functions (echo cannot return an array, and it is difficult to return the error reason when the function fails).

1. If an error occurs in the function, the description string of the error will be set to the variable result_errno=..., after which the function returns an error code return errno
2. If the function has a return value, set the return content to the variable result=...

# return value
if ! get_value; then
  echo "errno: $?"
  exit 1
fi
echo "value=$result"


# return array
if ! get_array; then
  echo "errno: $?"
  exit 1
fi
i=0
for val in "${result[@]}";do
    echo "value[$i] = $val"
    i=$((i+1))
done

declaration

A good function declaration tells humans how it should be used and what it will return. I provides functions declarations like 'typescript' format. Understanding how to understand the declaration is the most concise and fast way to master the use of functions, Here are some examples:

function strings_split(s: string, separators: string): []string

The strings_split function accepts two positional parameters, a string 's' and 'separators', and the function returns a string array after separating 's'.

(separator: string, ...s: []string): string

The above declaration omits the function name, which is usually written above the function in the source code, because the name already exists in the source code. In addition... s means variable length parameter.

(): errno

The errno return value indicates that this function is a discriminant, usually only for use with if, it has no return content

() (id: number, errno)

The above function returns a number to the result variable, and because of the existence of errno, this function may have an error return errno

(): panic
() (id: number, panic)

panic means that when the function fails, bash will be automatically terminated, and the call stack and available error messages will be printed

test

Only tested code should be used with confidence, especially bash Scripts are often used for system administration and can cause system crashes directly if not tested.

test.sh is a unit test tool I wrote for bash, it found in the source code starting with test_ prefix the function and execute, at the same time, some test-related information can be printed. There are many files suffixed with _test.sh under the dst folder, you can refer to them to write unit test code, dst/assert.sh some functions are provided to simplify the test code.

View instructions for use:

./test.sh -h

Test specified file:

./test.sh dst/strings_test.sh dst/path_test.sh

Test all files (*_test.sh) under the specified folder:

./test.sh
./test.sh -d dst