Bash script not running synchronously

Question

So I have a script that does attempts to create a sql file on the server, and then zips that file up. I'm having an issue where the GZip call is being executed before the file is written. The odd thing is that when I run this on my VM instance it's totally fine. But when I test it on one of the servers, nothing but fail.

 echo "Backing up $DB..."
 $PROG_MYSQLDUMP -u $USERNAME -p${PASSWORD} -h $HOST $DB $IGNORES > ${DEST_FILE}

 echo "Zipping file...${DEST_FILE}"
 $PROG_GZIP $DEST_FILE

The only idea I have is to add a check before the GZip call is made that checks for the file and goes on only is it's there else after like X checks fails. I don't like this solution. Is there something I'm missing to get the script to wait on its own?

Thanks.

Whatever you are seeing I guarantee you that $PROG_GZIP will not execute until $PROG_MYSQLDUMP has exited, meaning the file has been written (or not). — sorpigal
– sorpigal, Commented Oct 31, 2011 at 18:20

thejh · Accepted Answer · 2011-10-31 18:10:19Z

4

There's no way the gzip program could get started before the dump was written. Anyway, why aren't you piping the dump in gzip? This should save time and temporary disk space. Also, it would reduce the load on the disks.

$PROG_MYSQLDUMP -u $USERNAME -p${PASSWORD} -h $HOST $DB $IGNORES |
$PROG_GZIP > $DEST_FILE.gz

answered Oct 31, 2011 at 18:10

thejh

45.7k18 gold badges100 silver badges109 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Konerak Over a year ago

Haha, almost simultaneously. Have a +1 :)

Konerak · Accepted Answer · 2011-10-31 18:10:28Z

4

Or a pipeline? Evades the temporary file.

$PROG_MYSQLDUMP -u $USERNAME -p${PASSWORD} -h $HOST $DB $IGNORES | $PROG_GZIP >  ${DEST_FILE}

answered Oct 31, 2011 at 18:10

Konerak

39.8k13 gold badges102 silver badges121 bronze badges

Collectives™ on Stack Overflow

Bash script not running synchronously

2 Answers 2

1 Comment

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Related