[20190419]bash单双引号问题.txt
--//上午调试bash shell时遇到的问题。
$ sqlplus -s -l / as sysdba <<< '@ shared_latch.txt "test shared non-parent l0" 1 1 2 x 1' >| /tmp/xx.txt
$ cat /tmp/xx.txt
old 1: select decode(lower('&&5'),'s',8,'x',16,'8',8,'16',16) vmode from dual
new 1: select decode(lower('x'),'s',8,'x',16,'8',8,'16',16) vmode from dual
VMODE
----------
16
old 1: SELECT addr laddr FROM v$latch_parent WHERE NAME='&&1'
new 1: SELECT addr laddr FROM v$latch_parent WHERE NAME='test shared non-parent l0'
LADDR
----------------
0000000060009A18
Statement processed.
Function returned 1
Function returned 0
--//没有问题。如果写成脚本如下，我想使用<<<语法的主要原因是shared_latch.txt脚本最后没有exit语句。
--//如果我直接这样写sqlplus -s -l / as sysdba @ shared_latch.txt "test shared non-parent l0" 1 1 2 x 1
--//在完成后是无法退出的。
$ cat shared_latch.txt
/* 参数如下: @ shared_latch.txt latch_name willing why where mode sleep_num */
--//connect / as sysdba
col laddr new_value laddr
col vmode new_value vmode
select decode(lower('&&5'),'s',8,'x',16,'8',8,'16',16) vmode from dual ;
SELECT addr laddr FROM v$latch_parent WHERE NAME='&&1';
oradebug setmypid
oradebug call kslgetsl_w 0x&laddr &&2 &&3 &&4 &vmode
host sleep &&6
oradebug call kslfre 0x&laddr
--//exit
--//如果写成如下:
$ cat p7.sh
#! /bin/bash
vdate=$(date '+%Y%m%d%H%M%S')
echo $vdate
a="$1"
echo $a
source peek.sh "$1" 20 | timestamp.pl >| /tmp/peekx_${vdate}.txt &
sqlplus -s -l / as sysdba <
$(seq 20 | xargs -I {} echo -e '@latch_free \n host sleep 1')
EOF
sleep 1
# 参数如下: @ exclusive_latch.txt latch_name willing why where sleep_num
sqlplus / as sysdba <<< '@ shared_latch.txt "$a" 1 4 5 x 10' >| /tmp/xx.txt &
p=$!
strace -fttT -p $p -o /tmp/pp_${vdate}_${p}.txt > /dev/null &
sleep 2
sqlplus / as sysdba <<< '@ shared_latch.txt "$a" 1 6 7 s 5' >> /tmp/xx.txt &
p=$!
strace -fttT -p $p -o /tmp/pp_${vdate}_${p}.txt > /dev/null &
wait
--//检查 /tmp/xx.txt 内容,可以发现带入的内容并没有转换。
...
old 1: SELECT addr laddr FROM v$latch_parent WHERE NAME='&&1'
new 1: SELECT addr laddr FROM v$latch_parent WHERE NAME='$a'
--//可以发现外面的单引号发生作用，导致里面的双引号的内容不会转换，如何解决这个问题呢？
--//修改如下正常：
$ cat p7.sh
#! /bin/bash
vdate=$(date '+%Y%m%d%H%M%S')
echo $vdate
a="$1"
echo $a
source peek.sh "$1" 20 | timestamp.pl >| /tmp/peekx_${vdate}.txt &
sqlplus -s -l / as sysdba <
$(seq 20 | xargs -I {} echo -e '@latch_free \n host sleep 1')
EOF
sleep 1
# 参数如下: @ exclusive_latch.txt latch_name willing why where sleep_num
sqlplus / as sysdba <<< "@ shared_latch.txt '"$a"' 1 4 5 x 10" > /dev/null &
p=$!
strace -fttT -p $p -o /tmp/pp_${vdate}_${p}.txt > /dev/null &
sleep 2
sqlplus / as sysdba <<< "@ shared_latch.txt '"$a"' 1 6 7 s 5" > /dev/null &
p=$!
strace -fttT -p $p -o /tmp/pp_${vdate}_${p}.txt > /dev/null &
wait
$ . p7.sh "test shared non-parent l0"
20190419153743
test shared non-parent l0
Process 35246 attached - interrupt to quit
Process 35249 attached
Process 35252 attached
Process 35246 suspended
Process 35255 attached - interrupt to quit
Process 35257 attached
Process 35246 resumed
Process 35252 detached
Process 35276 attached
Process 35255 suspended
Process 35246 detached
Process 35249 detached
Process 35255 resumed
Process 35276 detached
Process 35255 detached
Process 35257 detached
[1] Done source peek.sh "$1" 20 | timestamp.pl >|/tmp/peekx_${vdate}.txt
[3] Done sqlplus / as sysdba <<< "@ shared_latch.txt '"$a"' 1 4 5 x 10" > /dev/null
[4] Done strace -fttT -p $p -o /tmp/pp_${vdate}_${p}.txt > /dev/null
[5]- Done sqlplus / as sysdba <<< "@ shared_latch.txt '"$a"' 1 6 7 s 5" > /dev/null
[6]+ Done strace -fttT -p $p -o /tmp/pp_${vdate}_${p}.txt > /dev/null
[2]+ Done sqlplus -s -l / as sysdba >|/tmp/latch_free_${vdate}.txt <
$(seq 20 | xargs -I {} echo -e '@latch_free \n host sleep 1')
EOF
--//有时候这些细节问题经常搞晕掉，浪费许多时间。
$ grep sem /tmp/pp_20190419153743_352*
/tmp/pp_20190419153743_35246.txt:35249 15:37:54.919702 semctl(315588608, 34, SETVAL, 0x1) = 0 <0.000029>
/tmp/pp_20190419153743_35255.txt:35257 15:37:46.890699 semop(315588608, 0x7fff45fe1820, 1) = 0 <8.029049>