[20200214]xargs与别名.txt

[20200214]xargs与别名.txt --//上午在优化sql语句时，发现xargs与alias的程序存在一点点小问题，做一个记录。 $ alias rrlsql='rlwrap sqlplus ' $ rrlsql -s -l scott/book @ ver1 <<< ' ' PORT_STRING                    VERSION        BANNER ------------------------------ -------------- -------------------------------------------------------------------------------- x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production $ echo @ver1 | xargs -I{} rrlsql scott/book {} xargs: rrlsql: No such file or directory --//也就是xargs不支持别名，应该是另外开一个shell,里面的环境与登录的bash shell环境不一致。 $ echo @ver1 | xargs -I{} sqlplus -s -l scott/book {} PORT_STRING                    VERSION        BANNER ------------------------------ -------------- -------------------------------------------------------------------------------- x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production $ alias ls alias ls='ls --color=auto --time-style=+"%Y-%m-%d %H:%M:%S"' $ echo bb1.txt | xargs ls -l -rw-r--r-- 1 oracle oinstall 230 Feb 12 16:03 bb1.txt $ ls -l bb1.txt -rw-r--r-- 1 oracle oinstall 230 2020-02-12 16:03:45 bb1.txt --//注意我显示的日期格式，执行时并没有现在别名ls。 https://stackoverflow.com/questions/34795432/using-xargs-to-pass-a-variable-to-alias-command https://stackoverflow.com/questions/979453/how-can-i-use-aliased-commands-with-xargs $ echo bb1.txt | xargs -IQ bash -c 'ls -l Q' -rw-r--r-- 1 oracle oinstall 230 Feb 12 16:03 bb1.txt --//不行。 $ echo bb1.txt | xargs -IQ bash -ic 'ls -l Q' -rw-r--r-- 1 oracle oinstall 230 2020-02-12 16:03:45 bb1.txt https://stackoverflow.com/questions/979453/how-can-i-use-aliased-commands-with-xargs Aliases are shell-specific - in this case, most likely bash-specific. To execute an alias, you need to execute bash, but aliases are only loaded for interactive shells (more precisely, .bashrc will only be read for an interactive shell). bash -i runs an interactive shell (and sources .bashrc). bash -c cmd runs cmd. --//我必须讲别名放入.bashrc文件中，重新登录打开新的终端： --//加入如下.bashrc. alias rrlsql='rlwrap sqlplus ' $ echo @ver1 | xargs -IQ bash -ci 'rrlsql -s -l scott/book Q' PORT_STRING                    VERSION        BANNER ------------------------------ -------------- -------------------------------------------------------------------------------- x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production --//OK!! --//在测试中我还遇到一个问题。 $ echo 4xamnunv51w9j | xargs -IQ bash -ci rrlsql -s -l scott/book @dpc Q '' SQL*Plus: Release 11.2.0.4.0 Production on Fri Feb 14 16:07:46 2020 Copyright (c) 1982, 2013, Oracle.  All rights reserved. Enter user-name: --//必须加双引号才OK。 $ echo 4xamnunv51w9j | xargs -IQ bash -ci "rrlsql -s -l scott/book @dpc Q ''" PLAN_TABLE_OUTPUT ------------------------------------- SQL_ID  4xamnunv51w9j, child number 0 ------------------------------------- select * from dept where deptno=10 Plan hash value: 2852011669 ---------------------------------------------------------------------------------------- | Id  | Operation                   | Name    | E-Rows |E-Bytes| Cost (%CPU)| E-Time   | ---------------------------------------------------------------------------------------- |   0 | SELECT STATEMENT            |         |        |       |     1 (100)|          | |   1 |  TABLE ACCESS BY INDEX ROWID| DEPT    |      1 |    20 |     1   (0)| 00:00:01 | |*  2 |   INDEX UNIQUE SCAN         | PK_DEPT |      1 |       |     0   (0)|          | ---------------------------------------------------------------------------------------- Query Block Name / Object Alias (identified by operation id): -------------------------------------------------------------    1 - SEL$1 / DEPT@SEL$1    2 - SEL$1 / DEPT@SEL$1 Predicate Information (identified by operation id): ---------------------------------------------------    2 - access("DEPTNO"=10) Note -----    - Warning: basic plan statistics not available. These are only collected when:        * hint 'gather_plan_statistics' is used for the statement or        * parameter 'statistics_level' is set to 'ALL', at session or system level 31 rows selected. argment : typical all advanced partition predicate remote note parallel projection alias peeked_binds outline adaptive --//另外的问题: --//我的rlsql定义的是函数 $ echo 4xamnunv51w9j | xargs -IQ  rlsql  -s -l scott/book @dpc Q '' Enter value for 2: SP2-0546: User requested Interrupt or EOF detected. argment : typical all advanced partition predicate remote note parallel projection alias peeked_binds outline adaptive --//最后1个参数''无法解析，加入引号或者\转义可以通过。 $ echo 4xamnunv51w9j | xargs -IQ  rlsql  -s -l scott/book @dpc Q "''" $ echo 4xamnunv51w9j | xargs -IQ  rlsql  -s -l scott/book @dpc Q \'\' $ echo 4xamnunv51w9j | xargs -IQ  rlsql  -s -l scott/book @dpc Q all