sed 查询特定内容

查询命令对照表

打印/etc/passwd中第10行的内容

sed -n '10p' /etc/passwd

　　

打印/etc/passwd中第8行开始，到第15行结束的内容

sed -n '8,15p' /etc/passwd

打印/etc/passwd中从第8行开始，然后+5行结束的内容

sed -n '8,+5p' passwd

打印/etc/passwd中开头匹配nginx字符的内容

sed -n '/^nginx/p' /etc/passwd

　　

打印/etc/passwd中开头为root的行开始，到ftp开头的行结束的内容

sed -n '/^root/,/^ftp/p' /etc/passwd

　　

打印/etc/passwd中第8行开始，到包含有/sbin/nologin的内容结束内容

sed -n '8,/\/sbin\/nologin/p' /etc/passwd

　　

打印/etc/passwd中第一个包含/bin/bash内容的行开始，到第5行结束的内容

sed -n '/\/bin\/bash/,5p' /etc/passwd

　　

练习脚本

需求描述： 处理一个类似MYSQL配置文件my.cnf的文本

示例如下：

• 编写脚本实现以下功能：输出文件有几个段，并且针对每个段可以统计配置参数总个数

预想输出结果：

• 1：client 2
• 2: server 12
• 3: mysqld 12
• 4: mysqld_safe 7
• 5: embedded 8
• 6: mysqld-5.5 9

[client]
port                                                        =
socket                                                      = /tmp/mysql.sock

# The MySQL server
[mysqld]
user                                                        = mysql
port                                                        =
bind-address                                                = 0.0.0.0
socket                                                      = /tmp/mysql.sock
datadir                                                     = /data/mysql_data
pid-file                                                    = /data/mysql_data/mysql.pid
basedir                                                     = /usr/local/mysql
tmpdir                                                      = /tmp

#此开关默认为NULL，即不允许导入导出。
#secure-file-priv                                           = /opt/upload

#-------------------------------gobal variables------------------------#
#默认关闭，涉及到timestamp类型的列自动更新的问题
explicit_defaults_for_timestamp                 =
###transaction_write_set_extraction              = XXHASH64  #以便在server收集写集合的同时将其记录到二进制日志。并且是行更改后的唯一标识此标识将用于检测冲突。
###loose-group_replication_group_name            = 'ce9be252-2b71-11e6-b8f4-00212889f856' #组的名字可以随便起,但不能用主机的GTID
###loose-group_replication_start_on_boot         = off  #为了避免每次启动自动引导具有相同名称的第二个组,所以设置为OFF。
###loose-group_replication_bootstrap_group       = off #同上
###loose-group_replication_local_address         = '192.168.1.88:33071' #写自己主机所在IP
###loose-group_replication_group_seeds           ='192.168.1.88:33071,192.168.1.89:33071,192.168.1.90:33071'
###loose-group_replication_single_primary_mode   = off  #关闭单主模式的参数
###loose-group_replication_enforce_update_everywhere_checks = on #开启多主模式的参数

skip-external-locking
skip-name-resolve
skip-ssl

#memory is 16G
key_buffer_size                                             = 32M
table_open_cache                                            =
table_definition_cache                                      =
sort_buffer_size                                            = 4M
net_buffer_length                                           = 32K
read_buffer_size                                            = 4M
read_rnd_buffer_size                                        = 16M

open_files_limit                                            =
thread_cache_size                                           =
query_cache_type                                            =
query_cache_size                                            = 32M
max_write_lock_count                                        =
wait_timeout                                                =
interactive_timeout                                         =
net_read_timeout                                            =
net_write_timeout                                           = 

max_connections                                             =
max_user_connections                                        =
max_connect_errors                                          =
max_allowed_packet                                          = 512M
back_log                                                    =
log_timestamps                                              = system
performance_schema                                          = OFF
character_set_server                                        = utf8mb4

##当链接数耗尽后，通过设置别用端口，让root可以登录
extra_max_connections                                       =
extra_port                                                  = 

###让mysql不区分大小写敏感
lower_case_table_names                                      = 

#explicit_defaults_for_timestamp                            = 

#----------------Myisam--------------------------------#
myisam_recover_options                                      = DEFAULT
bulk_insert_buffer_size                                     = 64M
myisam_sort_buffer_size                                     = 128M
myisam_max_sort_file_size                                   = 512M
myisam_repair_threads                                       = 

#if the query is exec time great than 2 seconds, the query will log to slow log if slowlog is enabled.
long_query_time                                             =
slow_query_log                                              = On
slow-query-log-file                                         = /data/mysql_data/slow.log
show_compatibility_56                                       = on

# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
#
#skip-networking

#----------------------------MySQL Log----------------#
# Replication Master Server (default)
# binary logging is required for replication
log-bin                                                     = mysql-bin
expire_logs_days                                            =
log_error                                                   = error.log
log_error_verbosity                                         =
log_warnings                                                = 

# binary logging format - mixed recommended
binlog_format                                               = row
relay-log                                                   = mysql-relay-bin
relay-log-index                                             = relay.index
# required unique id between  and ^ -
server-id                                                   =
#sql-mode                                                    = "NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
#sql-mode                                                    = "NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
sync_binlog                                                 =
log_slave_updates                                           =
#binlog_checksum                                            = NONE

#------------------------------replicate--------------#
#排除不需要同步的库表
#replicate-ignore-db                                        = mysql
#replicate-ignore-db                                        = sys
replicate-ignore-db                                         = information_schema
replicate-ignore-db                                         = performance_schema
replicate-ignore-db                                         = undolog
replicate-ignore-db                                         = for_nagios
replicate-ignore-db                                         = undolog

#replicate_wild_ignore_table                                = mysql.%
#replicate_wild_ignore_table                                = sys.%
replicate_wild_ignore_table                                 = information_schema.%
replicate_wild_ignore_table                                 = performance_schema.%
replicate_wild_ignore_table                                 = undolog.%
replicate_wild_ignore_table                                 = for_nagios.%
replicate_wild_ignore_table                                 = undolog.%

#主主复制需要开启
#auto_increment_offset=
#auto_increment_increment= 

#GTID模式复制，需要开启如下
gtid_mode                                                  = ON
enforce_gtid_consistency                                   = ON

#并发复制
slave-parallel-type                                         = LOGICAL_CLOCK
slave-parallel-workers                                      =
master_info_repository                                      = TABLE
relay_log_info_repository                                   = TABLE
relay_log_recovery                                          = ON

#跳过slave进程启动参数
skip-slave-start

#如果实例为从库，则需要设置为on
#read_only                                                   = on

#skip-grant-tables

#--------------------------------------------------------innoDB------------#
innodb_rollback_on_timeout
# Uncomment the following if you are using InnoDB tables
innodb_data_home_dir                                        = /data/mysql_data
innodb_data_file_path                                       = ibdata1:1G;ibdata2:1G:autoextend
innodb_log_group_home_dir                                   = /data/mysql_data
innodb_undo_directory                                       = /data/mysql_data/undolog/
innodb_undo_logs                                            =
innodb_undo_tablespaces                                     = 

# You can set .._buffer_pool_size up to  -  %
#innodb_use_sys_malloc =
#innodb_page_size =
innodb_buffer_pool_size                                     = 3G
innodb_buffer_pool_instances                                =
#innodb_additional_mem_pool_size = 8M

# Set .._log_file_size to  % of buffer pool size
innodb_log_file_size                                        = 256M
innodb_log_buffer_size                                      = 64M
innodb_log_files_in_group                                   =
#每次事务提交时MySQL都会把log buffer的数据写入log file，并且flush(刷到磁盘)中去，该模式为系统默认
innodb_flush_log_at_trx_commit                              =
innodb_lock_wait_timeout                                    =
#启用独立表空间
innodb_file_per_table                                       = 

#CPU是1颗8核的，那么可以设置
innodb_read_io_threads                                      =
innodb_write_io_threads                                     = 

#默认是0，则表示没有并发线程数限制，所有请求都会直接请求线程执行，当并发用户线程数量小于64，建议设置innodb_thread_concurrency=，在大多数情况下，最佳的值是小于并接近虚拟CPU的个数
innodb_thread_concurrency                                   =
innodb_max_dirty_pages_pct                                  =
innodb_flush_method                                         = O_DIRECT

innodb_purge_threads                                        =
innodb_large_prefix                                         = 

#参数待测试
#innodb_io_capacity                                         =
#innodb_io_capacity_max                                     = 

#根据CPU核心数来设定
thread_pool_size                                            =
#thread_handling = pool-of-threads
thread_pool_oversubscribe                                   = 

#thread_handling                             = pool-of-threads
thread_pool_stall_limit                                     =
thread_pool_max_threads                                     = 

#解释： 在启动时把热数据加载到内存。
innodb_buffer_pool_load_at_startup                          =
#解释： 在关闭时把热数据dump到本地磁盘
innodb_buffer_pool_dump_at_shutdown                         = 

##默认是8M, 如果一次insert数据量比较多的话, 可以适当增加
innodb_autoextend_increment                                 = 

[mysqldump]
quick
max_allowed_packet                                          = 512M

[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates

[myisamchk]
#key_buffer_size = 20M
#sort_buffer_size = 20M
key_buffer_size                                             = 200M
sort_buffer_size                                            = 200M
read_buffer                                                 = 2M
write_buffer                                                = 2M

[mysqld_safe]
#控制文件打开数的show global status like 'open%file%';比较合适的设置：Open_files / open_files_limit * % <= %
open-files-limit                                            =
log-error                                                   = /data/mysql_data/error.log

[mysqlhotcopy]
interactive-timeout

my.cnf

根据需求需要编写 2 个函数

• function get_all_segment  获取所有配置项的段名
• function count_items_in_segment 获取所有段名的配置个数

get_all_segment  函数实现思路

找到所有段名

sed -n '/\[.*\]/p' my.cnf | sed -e 's/\[//g' -e 's/\]//g'

.代表任意一个字符，*代表0个或多个字符，.*合起来就是任意字符(包括空) ,-e 可以连着使用多次

　　

mysql_process.sh

#!/bin/bash
#

FILE_NAME=/home/roo/Desktop/shell_code/day6/my.cnf
# 获取所有的片段
function get_all_segments
    {
        echo `sed -n '/\[.*\]/p' $FILE_NAME | sed -e 's/\[//g' -e 's/\]//g'`
    }

for item in `get_all_segments`
do
     echo $item

done

　　

count_items_in_segment  函数实现思路

找到指定段中的内容

找到 [client] 段 过滤掉以 # 开头的行和空行 然后过滤掉 [.*]  剩下的就是中间的内容了

sed -n '/\[client\]/,/\[.*\]/p' my.cnf |grep -v '^#' | grep -v '^$' | grep -v '\[.*\]'

统计函数

sed -n '/\[client\]/,/\[.*\]/p' my.cnf |grep -v '^#' | grep -v '^$' | grep -v '\[.*\]' | wc -l

完整的脚本

mysql_process.sh

    #!/bin/bash
    #

    FILE_NAME=/home/roo/Desktop/shell_code/day6/my.cnf
    # 获取所有的片段
    function get_all_segments
    {
        echo `sed -n '/\[.*\]/p' $FILE_NAME | sed -e 's/\[//g' -e 's/\]//g'`
    }
    # 统计单个片段 配置行数
    function count_items_in_segment
    {
        # 找到[xxx]并且下一个 [.*] 的项中间的内容就是一段配置
        items=`sed -n '/\['$1'\]/,/\[.*\]/p' "$FILE_NAME" | grep -v "^$" | grep -v "^#" | grep -v "\[.*\]"| wc -l`
        echo $items
        # for 循环打印并计算my.cnf每一行的配置，适合配置项之间没有空格的情况
        #index=0
        #for item in $items;
        #do
        #    index=`expr $index + 1`
        #done

        #echo $index

    }

    number=0
    for segment in `get_all_segments`
    do
        number=`expr $number + 1`
        # 将每个片段当做参数传进来计算
        items_count=`count_items_in_segment $segment`
        echo "$number: $segment $items_count"
    done