swap.sh

e7e3fd8f · Andrei Kirushchanka · b9385e43 · b9385e43
Verified Commit e7e3fd8f authored 5 years ago by Andrei Kirushchanka
--- a/swap.sh
+++ b/swap.sh
-#!/bin/sh
-# System utilities: dd, mount, mkswap, swapon, swapoff, chmod, cat, grep, echo, rm, cp, mv, exit
-# Global variables
-SWAP_FILE="${SWAP_FILE:=/swapfile}"
-SWAP_FILE_PERM=0600
-SWAP_ACTION_DEFAULT='help'
-SWAP_ACTION="${SWAP_ACTION:=$1}"
-SWAP_SIZE_DEFAULT_MAX=64
-SWAP_SIZE_DEFAULT_MIN=1
-SWAP_SIZE_DEFAULT=$((SWAP_SIZE_DEFAULT_MAX / 16))
-SWAP_SIZE=${SWAP_SIZE:=$2}
-SWAP_BLOCK_SIZE_DEFAULT_MAX=16384
-SWAP_BLOCK_SIZE_DEFAULT_MIN=512
-SWAP_BLOCK_SIZE_DEFAULT=$SWAP_BLOCK_SIZE_DEFAULT_MIN
-SWAP_BLOCK_SIZE=${SWAP_BLOCK_SIZE:=$3}
-FSTAB_FILE='/etc/fstab'
-FSTAB_BAKCUP_FILE="${FSTAB_FILE}.back"
-FSTAB_SWAP_FILE="${FSTAB_FILE}.swapfile"
-FSTAB_SWAP_FILE_LINE="${SWAP_FILE}       none       swap       sw       0 0"
-####    HELP
-# Help message
-swap_file_help_message()
-{
-    cat << _H_E_L_P
-Usage: swap.sh [action] [swap_size] [swap_block_size]
-SWAP file create/remove on the system.
-Actions (by default: help):
-  c, create  SWAP file create. By default: ${SWAP_FILE}
-  r, remove  SWAP file remove. By default: ${SWAP_FILE}
-  h, help    Print this message.
-Arguments:
-  [swap_size]        Set size of SWAP file (gigabytes).
-                       By default: ${SWAP_SIZE_DEFAULT}, min=${SWAP_SIZE_DEFAULT_MIN}, max=${SWAP_SIZE_DEFAULT_MAX}.
-  [swap_block_size]  Set block size of SWAP file (bytes).
-                       By default: ${SWAP_BLOCK_SIZE_DEFAULT}, min=${SWAP_BLOCK_SIZE_DEFAULT_MIN}, max=${SWAP_BLOCK_SIZE_DEFAULT_MAX}.
-Environment variables:
-  SWAP_FILE        Set full path of SWAP file.
-  SWAP_ACTION      Set action for the script running.
-  SWAP_SIZE        Set size of SWAP file.
-  SWAP_BLOCK_SIZE  Set block size of SWAP file.
-  SWAP_FILE        Set SWAP file path.
-_H_E_L_P
-}
-# Print help message
-swap_file_help()
-{
-    swap_file_help_message
-    exit 0
-}
-# Print help, error message and exit
-swap_file_error()
-{
-    swap_file_help_message
-    echo ''
-    echo "ERROR: $*"
-    exit 1
-}
-####    DEFINITION (action, size, block size)
-# SWAP size check as integer
-_size_check_as_integer()
-{
-    if [ -z "$1" ]; then
-        swap_file_error "SWAP ${2}size is empty"
-    else
-        echo "$1" | grep -Eq '^[0-9]+$' > /dev/null
-        if [ ! $? -eq 0 ]; then
-            swap_file_error "Invalid SWAP ${2}size '$1'." "Must be integer"
-        fi
-    fi
-}
-# Min size check
-_size_check_as_min()
-{
-    if [ $2 -gt $1 ]; then
-        swap_file_error "Invalid SWAP ${3}size '$1'." "Must be min=$2"
-    fi
-}
-# Max size check
-_size_check_as_max()
-{
-    if [ $1 -gt $2 ]; then
-        swap_file_error "Invalid SWAP ${3}size '$1'." "Must be max=$2"
-    fi
-}
-# SWAP action define/check
-swap_file_action_define()
-{
-    case "$SWAP_ACTION" in
-        create | c )
-            SWAP_ACTION='create'
-        ;;
-        remove | r )
-            SWAP_ACTION='remove'
-        ;;
-        help | h | '' )
-            SWAP_ACTION="$SWAP_ACTION_DEFAULT"
-        ;;
-        * )
-            swap_file_error "Invalid action '$SWAP_ACTION'"
-        ;;
-    esac
-}
-# SWAP size define/check
-swap_file_size_define()
-{
-    case "$SWAP_SIZE" in
-        '' )
-            SWAP_SIZE=$SWAP_SIZE_DEFAULT
-        ;;
-        * )
-            swap_file_size_check
-        ;;
-    esac
-}
-# SWAP size check
-swap_file_size_check()
-{
-    _size_check_as_integer "$SWAP_SIZE" ''
-    _size_check_as_min "$SWAP_SIZE" "$SWAP_SIZE_DEFAULT_MIN" ''
-    _size_check_as_max "$SWAP_SIZE" "$SWAP_SIZE_DEFAULT_MAX" ''
-}
-# SWAP block size define/check
-swap_file_block_size_define()
-{
-    case "$SWAP_BLOCK_SIZE" in
-        '' )
-            SWAP_BLOCK_SIZE=$SWAP_BLOCK_SIZE_DEFAULT
-        ;;
-        * )
-            swap_file_block_size_check
-        ;;
-    esac
-}
-# SWAP block size check
-swap_file_block_size_check()
-{
-    local x_block_size=$SWAP_BLOCK_SIZE_DEFAULT_MIN
-    local str_block='block '
-    _size_check_as_integer "$SWAP_BLOCK_SIZE" "$str_block"
-    _size_check_as_min "$SWAP_BLOCK_SIZE" "$SWAP_BLOCK_SIZE_DEFAULT_MIN" "$str_block"
-    _size_check_as_max "$SWAP_BLOCK_SIZE" "$SWAP_BLOCK_SIZE_DEFAULT_MAX" "$str_block"
-    # Validation
-    while true; do
-        if [ "$x_block_size" = "$SWAP_BLOCK_SIZE" ]; then
-            break
-        else
-            # Block size error
-            if [ $x_block_size -gt $SWAP_BLOCK_SIZE ]; then
-                swap_file_error "Invalid SWAP block size '$SWAP_BLOCK_SIZE'." \
-                    "Must be '$x_block_size'"
-            fi
-        fi
-        x_block_size=$(($x_block_size * 2))
-    done
-}
-####    SWAP CREATION
-# SWAP file create on system
-swap_file_create_on_system()
-{
-    local block_size=$(($SWAP_SIZE * 1024 * 1024 * 1024 / $SWAP_BLOCK_SIZE))
-    echo "SWAP file creating..."
-    dd if=/dev/zero of=$SWAP_FILE bs=$SWAP_BLOCK_SIZE count=$block_size status=progress
-    if [ $? -eq 0 ]; then
-        chmod $SWAP_FILE_PERM "$SWAP_FILE"
-        echo "File '$SWAP_FILE' has been created"
-    else
-        swap_file_error "File '$SWAP_FILE' has not been created"
-    fi
-}
-# SWAP make
-swap_file_make()
-{
-    mkswap "$SWAP_FILE"
-    if [ ! $? -eq 0 ]; then
-        swap_file_error "SWAP has not been maked"
-    fi
-    swapon "$SWAP_FILE"
-    if [ ! $? -eq 0 ]; then
-        swap_file_error "SWAP file has not been swiched on"
-    fi
-}
-# SWAP file create
-swap_file_create()
-{
-    if [ -f "$SWAP_FILE" ]; then
-        swap_file_error "File '$SWAP_FILE' already exists"
-    fi
-    swap_file_create_on_system
-    swap_file_make
-    cp "$FSTAB_FILE" "$FSTAB_BAKCUP_FILE"
-    if [ ! $? -eq 0 ]; then
-        echo "WARNING: Backup file '$FSTAB_BAKCUP_FILE' has not been created"
-    fi
-    echo "$FSTAB_SWAP_FILE_LINE" >> "$FSTAB_FILE"
-    if [ $? -eq 0 ]; then
-        mount -a
-        echo "SWAP file has been created"
-    else
-        swap_file_error "SWAP file has not been added in '$FSTAB_FILE'"
-    fi
-}
-####    SWAP REMOVING
-# /etc/fstab (FSTAB_FILE) restore
-swap_file_restore_fstab()
-{
-    cp "$FSTAB_FILE" "$FSTAB_SWAP_FILE"
-    if [ -f "$FSTAB_BAKCUP_FILE" ]; then
-        mv "$FSTAB_BAKCUP_FILE" "$FSTAB_FILE"
-    else
-        grep -vwE "$SWAP_FILE" "$FSTAB_SWAP_FILE" > "$FSTAB_FILE"
-        if [ ! $? -eq 0 ]; then
-            swap_file_error "File '$FSTAB_FILE' has not been updated without SWAP file"
-        fi
-    fi
-    mount -a
-}
-# SWAP file remove from /etc/fstab (FSTAB_FILE)
-swap_file_remove_from_fstab()
-{
-    cat $FSTAB_FILE | grep "$SWAP_FILE" > /dev/null
-    if [ $? -eq 0 ]; then
-        swap_file_restore_fstab
-    else
-        echo "WARNING: File '$SWAP_FILE' does not exist in '$FSTAB_FILE'"
-    fi
-}
-# SWAP file remove
-swap_file_remove()
-{
-    echo "SWAP file removing..."
-    swap_file_remove_from_fstab
-    if [ ! -f "$SWAP_FILE" ]; then
-        swap_file_error "File '$SWAP_FILE' does not exist"
-    fi
-    swapoff "$SWAP_FILE"
-    if [ $? -eq 0 ]; then
-        rm -f "$SWAP_FILE"
-        echo "File '$SWAP_FILE' has been removed"
-    else
-        swap_file_error "SWAP OFF is failed"
-    fi
-}
-####    MAIN
-# Main function
-swap_file()
-{
-    swap_file_action_define
-    swap_file_block_size_define
-    swap_file_size_define
-    swap_file_$SWAP_ACTION
-}
-# Execution if defined that
-if [ -f "$0" ]; then
-    swap_file
-    exit 0
-fi