Shell script: substitute a file's content according to a map?
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Now I can only use shell script to get one line every time and do substitution:
_map_num=`wc -l $_map | cut -d" " -f1`
while [ $i -le $_map_num ]; do
line=`sed -n "$i p" $_map`
<Do substitution by $line>
i=`expr $i + 1`
But I think this is not efficient because the sed will process the $_map file every time to get a line. Is there any way that I can just achieve the goal to process 2 files in 1 time just use awk? Or is there any other ways to make it more efficient?
More detail, I have written a script to generate SQL from a template and a string map(I will use it to generate SQL automatically and query MySQL database with "mysql" continously for testing in my project). So the next time, if I will test another database, I don't need to change the code, but give a different template and map.
This database have 7 types tables, and every type have 31 tables. There is a hash program to determine which to insert.
and The map file like this:
NUM: cmd(random_int 0 32 %04d)
ACCOUNT: cmd(random_str "a b c d e f g h i j k l m n o p q r s t u v w x y z - _ @ 1 2 3 4 5 6 7 8 9 0")
PASSWD: cmd(random_str "a b c d e f g h i j k l m n o p q r s t u v w x y z 1 2 3 4 5 6 7 8 9 0 - = _ + @ % , . ; A B C D E J G H I J K L M N O P Q R S T U V W X Y Z")
MD5: cmd(random_str "a b c d e f g h i j k l m n o p q r s t u v w x y z 1 2 3 4 5 6 7 8 9 0 - = _ + @ % , . ;" | md5sum | cut -d" " -f1)
STR: cmd(random_str "a b c d e f g h i j k l m n o p q r s t u v w x y z - _ @ 1 2 3 4 5 6 7 8 9 0 - = + % , . ÖÜ Åô ÖÐ ÎÄ ; Ç¨¤ ¨®¨¨ ¨®Ò ÂÌ Ë¨° ÒÂ Ð¡À ¡¤ç Ï¸ Ó¨º ²» Ð¨¨ ¹¨¦ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z")
DATE: cmd(date -d "`random_str 0 $RANDOM` days ago" -I)
IDNUM: cmd(expr $(random_int 0 1000000))
The script will looks up the map and finds the srings to substitute, if it is cmd(.*), then it will execute it as a shell command by "eval", and the result will be the string to replace. The script like this:
Before I have tried to get random words from /usr/share/dict/linux.words, also slow for the same reason.
Now it is about generating 1 SQL transaction per sec(90s~2min for 105 transactions). I tested using "while read", It could only make it faster about 10~20 seconds, and if I use:
in the "while read", I could get the right result every cycle, but I don't know how to get it from the circulation with high performance!
And I think anothor problem is that: it must assign the _result variable every time, and this make the low efficiency.
Maybe I will rebuild it with python, I'm learning that. But before that, I want to try to test the concurrency: If I could run 20 copies of that script at the same time, what about the result?
Originally posted by bigearsbilly you could always try converting it to a dbm database if you have time, it's very simple and very quick.
Could you give me some details?
I have tried the concurrency, and no effect. Even I write a simple C program that fork child processes to do the task!
In fact, I found that if I fork 5 child processes, The program will wait about 5 seconds, and 20 seconds for 20 childs. The execution becames not averagely, and the total time was near to the results before.