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 = 3306 socket = /tmp/mysql.sock # The MySQL server [mysqld] user = mysql port = 3306 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 = 1 ###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 = 2048 table_definition_cache = 1024 sort_buffer_size = 4M net_buffer_length = 32K read_buffer_size = 4M read_rnd_buffer_size = 16M open_files_limit = 10000 thread_cache_size = 400 query_cache_type = 0 query_cache_size = 32M max_write_lock_count = 300 wait_timeout = 120 interactive_timeout = 120 net_read_timeout = 120 net_write_timeout = 120 max_connections = 800 max_user_connections = 750 max_connect_errors = 10000 max_allowed_packet = 512M back_log = 2048 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 = 2 extra_port = 13306 ###让mysql不区分大小写敏感 lower_case_table_names = 1 #explicit_defaults_for_timestamp = 1 #----------------Myisam--------------------------------# myisam_recover_options = DEFAULT bulk_insert_buffer_size = 64M myisam_sort_buffer_size = 128M myisam_max_sort_file_size = 512M myisam_repair_threads = 1 #if the query is exec time great than 2 seconds, the query will log to slow log if slowlog is enabled. long_query_time = 1 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 = 20 log_error = error.log log_error_verbosity = 1 log_warnings = 1 # binary logging format - mixed recommended binlog_format = row relay-log = mysql-relay-bin relay-log-index = relay.index # required unique id between 1 and 2^32 - 1 server-id = 1 #sql-mode = "NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION" #sql-mode = "NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION" sync_binlog = 1 log_slave_updates = 1 #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= 2 #auto_increment_increment= 2 #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 = 2 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 = 128 innodb_undo_tablespaces = 3 # You can set .._buffer_pool_size up to 50 - 80 % #innodb_use_sys_malloc = 0 #innodb_page_size = 8192 innodb_buffer_pool_size = 3G innodb_buffer_pool_instances = 1 #innodb_additional_mem_pool_size = 8M # Set .._log_file_size to 25 % of buffer pool size innodb_log_file_size = 256M innodb_log_buffer_size = 64M innodb_log_files_in_group = 3 #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 = 1 innodb_lock_wait_timeout = 120 #启用独立表空间 innodb_file_per_table = 1 #CPU是1颗8核的，那么可以设置 innodb_read_io_threads = 8 innodb_write_io_threads = 8 #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=0，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 = 12 innodb_max_dirty_pages_pct = 75 innodb_flush_method = O_DIRECT innodb_purge_threads = 10 innodb_large_prefix = 1 #参数待测试 #innodb_io_capacity = 20000 #innodb_io_capacity_max = 40000 #根据CPU核心数来设定 thread_pool_size = 8 #thread_handling = pool-of-threads thread_pool_oversubscribe = 24 #thread_handling = pool-of-threads thread_pool_stall_limit = 100 thread_pool_max_threads = 30 #解释： 在启动时把热数据加载到内存。 innodb_buffer_pool_load_at_startup = 1 #解释： 在关闭时把热数据dump到本地磁盘 innodb_buffer_pool_dump_at_shutdown = 1 ##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 = 32 [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 * 100% <= 75% open-files-limit = 65535 log-error = /data/mysql_data/error.log [mysqlhotcopy] interactive-timeout
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
