1.封装函数
#!/bin/bash
 
function log()
{
   echo "$@"
}
//测试：
log "this is a test..."
log "today is `date '+%Y-%m-%d'` "
2.设置时间日志
#!/bin/bash
 
function log()
{
   echo "$(date '+%Y-%m-%d %H:%M:%S') $@"
}
 
log "this is a test..."
3.设置日志级别，并输出对应日志
#!/bin/bash
 
#日志级别 debug-1, info-2, warn-3, error-4, always-5
LOG_LEVEL=3
 
#调试日志
function log_debug(){
  content="[DEBUG] $(date '+%Y-%m-%d %H:%M:%S') $@"
  [ $LOG_LEVEL -le 1  ] && echo -e "\033[32m"  ${content}  "\033[0m"
}
#信息日志
function log_info(){
  content="[INFO] $(date '+%Y-%m-%d %H:%M:%S') $@"
  [ $LOG_LEVEL -le 2  ] && echo -e "\033[32m"  ${content} "\033[0m"
}
#警告日志
function log_warn(){
  content="[WARN] $(date '+%Y-%m-%d %H:%M:%S') $@"
  [ $LOG_LEVEL -le 3  ] && echo -e "\033[33m" ${content} "\033[0m"
}
#错误日志
function log_err(){
  content="[ERROR] $(date '+%Y-%m-%d %H:%M:%S') $@"
  [ $LOG_LEVEL -le 4  ] && echo -e "\033[31m" ${content} "\033[0m"
}
#一直都会打印的日志
function log_always(){
   content="[ALWAYS] $(date '+%Y-%m-%d %H:%M:%S') $@"
   [ $LOG_LEVEL -le 5  ] && echo -e  "\033[32m" ${content} "\033[0m"
}
4.日志写入文件
#日志文件
LOG_FILE=./log.txt
function log(){
    content="$(date '+%Y-%m-%d %H:%M:%S') $@"
    echo $content >> $LOG_FILE
}

#!/bin/bash

#${FUNCNAME[1]代表调用该函数的函数，$LINENO代表当前代码行号
Log(){
    local log_level=$1
    local log_info=$2
    local line=$3
    local script_name=$(basename $0)

    case ${log_level} in
    "INFO")
        echo -e "\033[32m$(date "+%Y-%m-%d %T.%N") [INFO]: ${log_info}\033[0m";;
    "WARN")
        echo -e "\033[33m$(date "+%Y-%m-%d %T.%N") [WARN]: ${log_info}\033[0m";;
    "ERROR")
        echo -e "\033[31m$(date "+%Y-%m-%d %T.%N") [ERROR ${script_name} ${FUNCNAME[1]}:$line]: ${log_info}\033[0m";;
    *)
        echo -e "${@}"
    ;;
    esac
}

Log INFO "Install Success"
Log WARN "You Can Ignore"
Log ERROR "Invalid Param" $LINENO