shell编程系列10--文本处理三剑客之sed利用sed查询特定内容利用sed查找文件内容:    pattern种类：        1、8p        2、8,10p        3、8,+5p        4、/regexp/p        5、8,/regexp/p        6、/regexp/,8p    1、打印/etc/passwd中第10行的内容        sed -n '10p' /etc/passwd    2、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    3、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    4、打印/etc/passwd中开头匹配nginx字符的内容        sed -n '/^nginx/p' /etc/passwd    5、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            6、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    7、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1：    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    function get_all_segment    function count_items_in_segment    # .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    # sed -n '/\[.*\]/p' my.cnf | sed -e 's/\[//g' -e 's/\]//g'    client    mysqld    mysqldump    mysql    myisamchk    mysqld_safe    mysqlhotcopy    # 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 '\[.*\]'    port                                                        = 3306    socket                                                      = /tmp/mysql.sock    # 具体脚本    [root@localhost shell]# cat mysql_process.sh     #!/bin/bash    #    FILE_NAME=/data/shell/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'`    }    #get_all_segments        # 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 "\[.*\]"`        #sed -n '/\[client\]/,/\[.*\]/p' my.cnf |grep -v '^#' | grep -v '^$' | grep -v '\[.*\]'        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

my.cnf 示例

[client]port                                                        = 3306socket                                                      = /tmp/mysql.sock# The MySQL server[mysqld]user                                                        = mysqlport                                                        = 3306bind-address                                                = 0.0.0.0socket                                                      = /tmp/mysql.sockdatadir                                                     = /data/mysql_datapid-file                                                    = /data/mysql_data/mysql.pidbasedir                                                     = /usr/local/mysqltmpdir                                                      = /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-lockingskip-name-resolveskip-ssl#memory is 16Gkey_buffer_size                                             = 32Mtable_open_cache                                            = 2048table_definition_cache                                      = 1024sort_buffer_size                                            = 4Mnet_buffer_length                                           = 32Kread_buffer_size                                            = 4Mread_rnd_buffer_size                                        = 16Mopen_files_limit                                            = 10000thread_cache_size                                           = 400query_cache_type                                            = 0query_cache_size                                            = 32Mmax_write_lock_count                                        = 300wait_timeout                                                = 120interactive_timeout                                         = 120net_read_timeout                                            = 120net_write_timeout                                           = 120max_connections                                             = 800max_user_connections                                        = 750max_connect_errors                                          = 10000max_allowed_packet                                          = 512Mback_log                                                    = 2048log_timestamps                                              = systemperformance_schema                                          = OFFcharacter_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                                       = 2extra_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                                      = DEFAULTbulk_insert_buffer_size                                     = 64Mmyisam_sort_buffer_size                                     = 128Mmyisam_max_sort_file_size                                   = 512Mmyisam_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                                             = 1slow_query_log                                              = Onslow-query-log-file                                         = /data/mysql_data/slow.logshow_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 replicationlog-bin                                                     = mysql-binexpire_logs_days                                            = 20log_error                                                   = error.loglog_error_verbosity                                         = 1log_warnings                                                = 1# binary logging format - mixed recommendedbinlog_format                                               = rowrelay-log                                                   = mysql-relay-binrelay-log-index                                             = relay.index# required unique id between 1 and 2^32 - 1server-id                                                   = 1#sql-mode                                                    = "NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"#sql-mode                                                    = "NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"sync_binlog                                                 = 1log_slave_updates                                           = 1#binlog_checksum                                            = NONE#------------------------------replicate--------------##排除不需要同步的库表#replicate-ignore-db                                        = mysql#replicate-ignore-db                                        = sysreplicate-ignore-db                                         = information_schemareplicate-ignore-db                                         = performance_schemareplicate-ignore-db                                         = undologreplicate-ignore-db                                         = for_nagiosreplicate-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                                                  = ONenforce_gtid_consistency                                   = ON#并发复制slave-parallel-type                                         = LOGICAL_CLOCKslave-parallel-workers                                      = 2master_info_repository                                      = TABLErelay_log_info_repository                                   = TABLErelay_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 tablesinnodb_data_home_dir                                        = /data/mysql_datainnodb_data_file_path                                       = ibdata1:1G;ibdata2:1G:autoextendinnodb_log_group_home_dir                                   = /data/mysql_datainnodb_undo_directory                                       = /data/mysql_data/undolog/innodb_undo_logs                                            = 128innodb_undo_tablespaces                                     = 3# You can set .._buffer_pool_size up to 50 - 80 %#innodb_use_sys_malloc = 0 #innodb_page_size = 8192innodb_buffer_pool_size                                     = 3Ginnodb_buffer_pool_instances                                = 1#innodb_additional_mem_pool_size = 8M# Set .._log_file_size to 25 % of buffer pool sizeinnodb_log_file_size                                        = 256Minnodb_log_buffer_size                                      = 64Minnodb_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                              = 1innodb_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                                      = 8innodb_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                                   = 12innodb_max_dirty_pages_pct                                  = 75innodb_flush_method                                         = O_DIRECTinnodb_purge_threads                                        = 10innodb_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-threadsthread_pool_oversubscribe                                   = 24#thread_handling                             = pool-of-threadsthread_pool_stall_limit                                     = 100thread_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]quickmax_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 = 20Mkey_buffer_size                                             = 200Msort_buffer_size                                            = 200Mread_buffer                                                 = 2Mwrite_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                                            = 65535log-error                                                   = /data/mysql_data/error.log[mysqlhotcopy]interactive-timeout