mysqldump error: Cannot open 38: no such file

gabogabans

1/10/24, 10:20 PM

in my ubuntu server I want to do a mysql backup of my database, however I get the following error:

run-backup.sh: 10: run-backup.sh: cannot open 38: No such file

In my home directory I created a sql-backup directory, so I don't know what the error means...

Also is there a way for mysql to not ask to enter mysql passoword since I'm already providing $dbpass inside my shellscript file.

This is my shell script file (changed credentials):

#!/bin/bash
##this script will backup mysql and upload it to google drive 
##directory name
dirname=/home/GabotronES/sql-backups
##database name
database=wooloveapp
##database username
dbuser=GabotronES
##database password
dbpass=xxxxxxxxxxxxxxxxxxxxxxxx
## rclone remote name
remoteName=gabotrones
##spaces folder name
bucketFoldername=sql-backups
##todays date to add to new zip filename
datestring=$(date +\%Y_\%m_\%d_\%H)


mysqldump -u $dbuser -p$dbpass $database | gzip > "${dirname}/${database}-${datestring}.sql.gz"
##wait for 10 seconds
sleep 10

rclone --config=/home/GabotronES/gabotron.conf copy "${dirname}/${database}-${datestring}.sql.gz" $remoteName:$bucketFoldername

exit 0;

Thanks in advance.

146

1 + 2

20.04

steeldriver

1/10/24, 10:34 PM

Does dbpass contain a shell redirection character? something like `dbpass=xxx<38` for example? Regardless, you should quote the RHS of the assignment, like `dbpass='xxxxxxxxxx'`

gabogabans

1/10/24, 10:36 PM

actually yes, the password has <38 at the end... soI should quote the password then, what about the user, do I need to quote it too

Score:1

Ubuntu

steeldriver

1/10/24, 10:43 PM

If the line numbering is correct, then it indicates the error is in the assignment statement dbpass=xxxxxxxxxxxxxxxxxxxxxxxx

Because the RHS is not protected by quotes, the shell will try to interpret it. So for example if the password ends in <38 it will try to redirect standard input from a file named 38 in the current directory and (assuming no such file exists) you will get an error like:

$ bash -c 'dbpass=xxxxxxxxxxxxxxxxxxxxx<38'
bash: 38: No such file or directory

(in bash)

$ sh -c 'dbpass=xxxxxxxxxxxxxxxxxxxxx<38'
sh: 1: cannot open 38: No such file

(in sh)

The solution is to make sure you properly quote the string on the RHS of the assignment:

dbpass='xxxxxxxxxxxxxxxxxxxxxxxx'

For similar reasons you should also double quote variable expansions like mysqldump -u "$dbuser" -p"$dbpass" "$database"

For a more thorough discussion (including slightly different rules for other shells) see Security implications of forgetting to quote a variable in bash/POSIX shells

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