Bash – PHPor 的Blog

bash 之信号处理

缘起： docker stop 时往往会比较慢，起原因多半是docker 容器的init进程没有正确处理信号所 …

bash 之变量声明周期

有些时候，我们通过如下方式执行命令：

var=1 cmd.sh

1	var=1 cmd.sh

这样， …

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bash 之变量与函数

bash中有个export，可以导出变量给子进程使用；但是函数没法导出给子进程使用，如下：

tcp server in bash

我想通过nc+bash创建一个tcp server， nc负责收发数据，bash负责处理数据，如何将nc和ba …

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bash 之 printf

场景：

printf "%s\n" $(</proc/$pid/cmline)

1	printf "%s\n" $(</proc/$pid/cmline)

对于多个部分的命令行会打印到多行，如 …

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bash 获取所有pid

for d in /proc/*;do [[ $d =~ /proc/[0-9]+ ]] && echo ${d#/proc/};done

1	for d in /proc/*;do [[ $d =~ /proc/[0-9]+ ]] && echo ${d#/proc/};done

ls 可以list /proc …

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count words in bash without wc

如何计算字符串中单词的数量，但是不使用wc？ eg： [crayon-673d75cca43c53169853 …

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cfree ( free in container)

#!/bin/bash
CGROUP_DIR=/sys/fs/cgroup/memory
UNLIMITTED=9223372036854771712

read mem_total <$CGROUP_DIR/memory.limit_in_bytes
read mem_used <$CGROUP_DIR/memory.usage_in_bytes
mem_free=$((mem_total - mem_used))

read mem_swap_total <$CGROUP_DIR/memory.memsw.limit_in_bytes
read mem_swap_used <$CGROUP_DIR/memory.memsw.usage_in_bytes
swap_total=$((mem_swap_total - mem_total))
swap_used=$((mem_swap_used - mem_used))
swap_free=$((swap_total - swap_used))

if [[ $mem_total = "9223372036854771712" ]];then
	/usr/bin/free -h && exit
fi

printf "%20s%20s%20s\n" total used free
printf "Mem:%16s%20s%20s\n"  $((mem_total/1024/1024))M $((mem_used/1024/1024))M $((mem_free/1024/1024))M
printf "Swap:%15s%20s%20s\n"  $((swap_total/1024/1024))M $((swap_used/1024/1024))M $((swap_free/1024/1024))M

#!/bin/bash

CGROUP_DIR=/sys/fs/cgroup/memory

UNLIMITTED=9223372036854771712

read mem_total <$CGROUP_DIR/memory.limit_in_bytes

read mem_used <$CGROUP_DIR/memory.usage_in_bytes

mem_free=$((mem_total - mem_used))

read mem_swap_total <$CGROUP_DIR/memory.memsw.limit_in_bytes

read mem_swap_used <$CGROUP_DIR/memory.memsw.usage_in_bytes

swap_total=$((mem_swap_total - mem_total))

swap_used=$((mem_swap_used - mem_used))

swap_free=$((swap_total - swap_used))

if [[ $mem_total = "9223372036854771712" ]];then

/usr/bin/free -h && exit

printf "%20s%20s%20s\n" total used free

printf "Mem:%16s%20s%20s\n" $((mem_total/1024/1024))M $((mem_used/1024/1024))M $((mem_free/1024/1024))M

printf "Swap:%15s%20s%20s\n" $((swap_total/1024/1024))M $((swap_used/1024/1024))M $((swap_free/1024/1024))M

bash 对单行中的单词进行排序

排序一般使用sort命令，但是，sort命令是基于行的： [crayon-673d75cca46ed50953 …

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Shell Style Guide

https://google.github.io/styleguide/shell.xml 建议的bash风格 …

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