bash snippets

demo.sh

#!/bin/bash

# 显示脚本的各种调用命令
set -x
# 一但有任何一个语句返回非真的值，则退出bash
set -e
# 你使用未初始化的变量时，让bash自动退出
set -u

SCRIPT_PATH="${BASH_SOURCE[0]}";
while([ -L "${SCRIPT_PATH}" ]); do
    cd "`dirname "${SCRIPT_PATH}"`"
    SCRIPT_PATH="$(readlink "$(basename "${SCRIPT_PATH}")")";
done
cd "$(dirname "${SCRIPT_PATH}")" > /dev/null
SCRIPT_PATH="$(pwd)";

# 获取当前路径
CURRENT_DIR=$(cd `dirname $0`; pwd)
CURRENT_DIR=$(cd $(dirname ${BASH_SOURCE[0]}); pwd)

# 赋值变量的方法
TEST_ENV=${TEST_ENV:-"$CURRENT_DIR/../../test"}

# 简单的日志打印封装
LOG_FILE="$CURRENT_DIR/xxx.log"

# print log to stdout and log file
function log()
{
    echo "`date +"%Y-%m-%d %H:%M:%S"` $@"
    echo "`date +"%Y-%m-%d %H:%M:%S"` $@" >> $LOG_FILE
}

# 仅 bash 支持，<(cmd) 可以将 cmd 的输出作为一个文件参数，可以避免临时文件
cat <(ls)
# 在子进程中后台执行，没有 & 表示子进程执行
(ls)&

# 端口检测
# 检查端口是否被监听, 作为服务启动的标志
# check_port_listening $port
function check_port_listening
{
    max_check_times=20
    left_check_times=$max_check_times
    while [[ $left_check_times -gt 0 ]]
    do
        count=`netstat -anl 2>/dev/null | awk '/^tcp.*LISTEN/{split($4,addr,":");print addr[2]}' 2>/dev/null | grep -c "^$1$"`
        if [[ count -ne "0" ]]; then
            return $count
        else
            ((left_check_times--))
            sleep 1
        fi
    done
    # 没找的时候计数是0, 逻辑会到这里
    return 0
}

# 杀死pid的进程
# stop_process $pid_file
function stop_process()
{
    pid=$1
    shift
    # 最大重试次数
    max_check_times=20
    left_check_times=$max_check_times
    while [[ $left_check_times -gt 0 ]]
    do
        # 判断进程是否还活着, 死了就把pid文件删掉
        if [ `ps -ef|grep $pid|wc -l` != "0" ];then
            kill $pid
        else
            # 查看pid和pid_file是否匹配, 匹配就删除, 防止误删
            if [[ -f $pid_file && $pid -eq `cat $pid_file` ]]; then
                rm -f $pid_file
            fi
            break
        fi
        ((left_check_times--))
        # 等待一下
        sleep 1
    done
    # 最后来一次kill -9, 保证杀死释放端口
    if [ `ps -ef|grep $pid|wc -l` != "0" ];then
        kill -9 $pid
        # 查看pid和pid_file是否匹配, 匹配就删除, 防止误删
        if [[ -f $pid_file && $pid -eq `cat $pid_file` ]]; then
            rm -f $pid_file
        fi
    fi
}

# 日期遍历
start="2015-09-16"
end="2015-11-15"

# 正序
for ((i=0;`date -d "$start +$i days" +%s`<=`date -d "$end" +%s`;i++))
do
    log_date=`date -d "$start +$i days" +%Y%m%d`
    echo $log_date
done

# 逆序
for ((i=0;`date -d "$end -$i days" +%s`>=`date -d "$start" +%s`;i++))
do
    log_date=`date -d "$end -$i days" +%Y%m%d`
    echo $log_date
done

# colour macros
if [ -t 1 ]
then
    BLACK="$( echo -e "\e[30m" )"
    RED="$( echo -e "\e[31m" )"
    GREEN="$( echo -e "\e[32m" )"
    YELLOW="$( echo -e "\e[33m" )"
    BLUE="$( echo -e "\e[34m" )"
    PURPLE="$( echo -e "\e[35m" )"
    CYAN="$( echo -e "\e[36m" )"
    WHITE="$( echo -e "\e[37m" )"

    NORMAL="$( echo -e "\e[0m" )"
fi

_black()  { echo "$BLACK""$@""$NORMAL";}
_red()    { echo "$RED""$@""$NORMAL";}
_green()  { echo "$GREEN""$@""$NORMAL";}
_yellow() { echo "$YELLOW""$@""$NORMAL";}
_blue()   { echo "$BLUE""$@""$NORMAL";}
_purple() { echo "$PURPLE""$@""$NORMAL";}
_cyan()   { echo "$CYAN""$@""$NORMAL";}
_white()  { echo "$WHITE""$@""$NORMAL";}

# shell array
pid=()
index=0

# shell function
function run
{
    sleep ${1} >/dev/null 2>&1 </dev/null &
    pid[$[index++]]=$!
}

run 1
run 2
run 3
run 4
run 5
run 6

# 等待所有pid
for ((i=0;i<${index};i++))
do
    echo ${pid[$i]}
    wait ${pid[$i]} || echo "${pid[$i]} finished already."
done

# 并发执行多个命令
tmpfile=$$.fifo
mkfifo $tmpfile
exec 4<>$tmpfile
rm $tmpfile
procs=$1
s=`ls test*.py`
seq=($s)
#
{
    for (( i = 1;i<=${procs};i++ ))
    do
        echo;
    done
} >&4

for id in ${seq[*]}
do
      read
        (sh run_one_case.sh ${id};echo >&4) &
done <&4
wait

# 关闭文件描述符
exec 4>&-
rm -f $tmpfile