MySQL error in Bash - mysql

i'm trying to load some tables to mysql into a bash script so i have the followin code
DOMY="$MYSQL --user=xxxxx --password=xxxxx --database=$DBNAME"
for filename in $(cat $HPATH/toload.tables)
do
$DOMY < $filename 2>/dev/null
if [ $? -ne 0 ]
then
echo "#003|Error loading $filename"
exit 1
fi
done
if i see $? (echo $?) it give me 0 (zero) but the exit 1 is executed.
What i'm doin wrong?

You can't see what's wrong because you have /dev/null-ed standard error.
Also, you are using an unnecessarily complex and somewhat error-prone code pattern where you examine $? later. It would be better to just write something like:
for i in "$#"; do
if mysql -u root < $i; then
echo ok # do "ok" processing here
else
echo not so ok # error path
fi
done

Related

variable expansion in subshell in makefile fails

I have a makefile function inside a makefile (myfunction.mk):
.ONESHELL:
define call_script
set +x
mkdir -p $$(dirname $(2))
if [ ! -f $(2) ]; then
echo "" > $(2)
fi
REDIRECT='| tee -a'
echo '>> $(1)'
($(1) ???????? $(2))
RET_CODE=$$?
echo "exit_code is: $$RET_CODE"
if [ ! $$RET_CODE = 0 ]; then
echo "$(3) terminated with error $$RET_CODE"
exit $$RET_CODE
else
if [ ! -z "$(strip $(3))" ]; then
echo "$(3) done"
fi
fi
endef
this function call a script and append result to a log (which is created with its folder if non existing), the result of the script is append only if the makefile variable given as the 4th ($(4)) argument is equal to 'yes'.
you call it like this:
include myfunction.mk
OUTPUT_ENABLED ?= yes
target:
$(call call_script, echo "test", reports/mylog.log, "doing test", OUTPUT_ENABLED)
This works for the most part:
if i replace '????????' by '| tee -a', it works.
if i replace '????????' by $(REDIRECT), it fails.
if i replace '????????' by $$REDIRECT, it fails.
why?
note: running it from a shell /bin/sh: symbolic link to dash
note: of course i want to add a ifeq that allows me to check for $(4) and replace | tee -a by &>>
I'll assume that you use call in a recipe, not flat in your Makefile. There are few problems with your shell script. First, if you try the following on the command line:
mkdir -p reports
REDIRECT='| tee -a'
echo '>> echo "test"'
(echo "test" $REDIRECT reports/mylog.log)
you'll see that echo considers:
"test" $REDIRECT reports/mylog.log
as its arguments. They are expanded and echoed, which prints:
test | tee -a reports/mylog.log
on the standard output, not the effect you expected, I guess. You could, for instance, use eval. On the command line:
eval "echo "test" $REDIRECT reports/mylog.log"
Which, in your Makefile, would become:
eval "$(1) $$REDIRECT $(2)"
Next you should not quote the third parameter of call because the quotes will be passed unmodified and your script will be expanded by make as:
echo " "doing test" terminated with error $RET_CODE"
Again probably not what you want.
Third, you should avoid useless spaces in the parameters of call because they are preserved too (as you can see above between the first 2 double quotes):
.PHONY: foo
foo:
$(call call_script,echo "test",reports/mylog.log,doing test,OUTPUT_ENABLED)
And for your last desired feature, it would be slightly easier to pass the value of OUTPUT_ENABLED to call instead of its name, but let's go this way:
$ cat myfunction.mk
define call_script
set +x
mkdir -p $$(dirname $(2))
if [ ! -f $(2) ]; then
echo "" > $(2)
fi
if [ "$($(4))" = "yes" ]; then
REDIRECT='| tee -a'
else
REDIRECT='&>>'
fi
echo '>> $(1)'
eval "$(1) $$REDIRECT $(2)"
RET_CODE=$$?
echo "exit_code is: $$RET_CODE"
if [ ! $$RET_CODE = 0 ]; then
echo "$(3) terminated with error $$RET_CODE"
exit $$RET_CODE
else
if [ ! -z "$(strip $(3))" ]; then
echo "$(3) done"
fi
fi
endef
$ cat Makefile
.ONESHELL:
include myfunction.mk
OUTPUT_ENABLED ?= yes
target:
$(call call_script,echo "test",reports/mylog.log,doing test,OUTPUT_ENABLED)
Note that I moved the .ONESHELL: in the main Makefile because it is probably better to not hide it inside an included file. Up to you.
The most problematic issue here is that if you pipe your commands, the exit code is the exit code of the last command in a pipe, e.g false | tee foo.log will exit with 0 as tee will most probably succeed. Note also that pipe only redirects stdout, so your log will not contain any stderr messages unless explicitly redirected.
Considering that piping commands influence exit code and lack of portability of $PIPESTATUS (most specifically not being supported in dash), I would try to avoid piping commands and use a temporary file for gathering output, i.e.:
$ cat Makefile
# $(1) - script to execute
# $(2) - log file
# $(3) - description
define call_script
echo '>> $(1)'
$(if $(OUTPUT_ENABLED), \
$(1) > $#.log 2>&1; RET_CODE=$$?; mkdir -p $(dir $(2)); cat $#.log >> $(2); cat $#.log; rm -f $#.log, \
$(1); RET_CODE=$$? \
); \
echo "EXIT_CODE is: $${RET_CODE}"; \
if [ $${RET_CODE} -ne 0 ]; then $(if $(3),echo "$(3) terminated with error $${RET_CODE}";) exit $${RET_CODE}; fi; \
$(if $(3), echo "$(3) done.")
endef
good:
$(call call_script,echo "test",reports/mylog.log,doing test)
bad:
$(call call_script,mkdir /root/foo,reports/mylog.log,intentional fail)
ugly:
$(call call_script,bad_command,reports/mylog.log)
Regular call will not create the logs and will stop on errors:
$ make good bad ugly
echo '>> echo "test"'
>> echo "test"
echo "test"; RET_CODE=$? ; echo "EXIT_CODE is: ${RET_CODE}"; if [ ${RET_CODE} -ne 0 ]; then echo "doing test terminated with error ${RET_CODE}"; exit ${RET_CODE}; fi; echo "doing test done."
test
EXIT_CODE is: 0
doing test done.
echo '>> mkdir /root/foo'
>> mkdir /root/foo
mkdir /root/foo; RET_CODE=$? ; echo "EXIT_CODE is: ${RET_CODE}"; if [ ${RET_CODE} -ne 0 ]; then echo "intentional fail terminated with error ${RET_CODE}"; exit ${RET_CODE}; fi; echo "intentional fail done."
mkdir: cannot create directory ‘/root/foo’: Permission denied
EXIT_CODE is: 1
intentional fail terminated with error 1
make: *** [Makefile:19: bad] Error 1
Note that ugly was not built due to failure on bad. Now the same with the log:
$ make good bad ugly OUTPUT_ENABLED=1
echo '>> echo "test"'
>> echo "test"
echo "test" > good.log 2>&1; RET_CODE=$?; mkdir -p reports/; cat good.log >> reports/mylog.log; cat good.log; rm -f good.log; echo "EXIT_CODE is: ${RET_CODE}"; if [ ${RET_CODE} -ne 0 ]; then echo "doing test terminated with error ${RET_CODE}"; exit ${RET_CODE}; fi; echo "doing test done."
test
EXIT_CODE is: 0
doing test done.
echo '>> mkdir /root/foo'
>> mkdir /root/foo
mkdir /root/foo > bad.log 2>&1; RET_CODE=$?; mkdir -p reports/; cat bad.log >> reports/mylog.log; cat bad.log; rm -f bad.log; echo "EXIT_CODE is: ${RET_CODE}"; if [ ${RET_CODE} -ne 0 ]; then echo "intentional fail terminated with error ${RET_CODE}"; exit ${RET_CODE}; fi; echo "intentional fail done."
mkdir: cannot create directory ‘/root/foo’: Permission denied
EXIT_CODE is: 1
intentional fail terminated with error 1
make: *** [Makefile:19: bad] Error 1
$ cat reports/mylog.log
test
mkdir: cannot create directory ‘/root/foo’: Permission denied
Note that this time ugly was also not run. But if run later, it will correctly append to the log:
$ make ugly OUTPUT_ENABLED=1
echo '>> bad_command'
>> bad_command
bad_command > ugly.log 2>&1; RET_CODE=$?; mkdir -p reports/; cat ugly.log >> reports/mylog.log; cat ugly.log; rm -f ugly.log; echo "EXIT_CODE is: ${RET_CODE}"; if [ ${RET_CODE} -ne 0 ]; then exit ${RET_CODE}; fi;
/bin/sh: 1: bad_command: not found
EXIT_CODE is: 127
make: *** [Makefile:22: ugly] Error 127
$ cat reports/mylog.log
test
mkdir: cannot create directory ‘/root/foo’: Permission denied
/bin/sh: 1: bad_command: not found
Personally I am not fan of implementing logging in this way. It is complicated and it only logs output of commands, not make output itself, and only of those commands which are explicitly called to do so. I'd rather keep Makefile clean and simple and just run make 2>&1 | tee log instead to have the output logged.

Mysql error handling in queries bash script

I need to catch any invalid credentials while connecting to MariaDB, and overwrite the stderr stream explaining the error.
I have tried to use the following since it seemed to be the easiest and shortest code, but the database throws it's own error instead of displaying mine so I do not think the condition is even working.
right after the mysql command
if [ "$?" -eq 0 ]; then
echo "There is something wrong with the arguments provided">&2
exit 2
else
: #some code
fi
TABLES=$(mysql --skip-column-name -u $USER -pPASSWORD $DB -e "SHOW TABLES;" | grep -v '+' | cut -d' ' -f2)
if [ "$?" -eq- 0 ]; then
echo "There is something wrong with the arguments provided">&2
exit 2
else
: #some code
fi
I was expecting to see my stderr message appearing instead it is showing the mariadb error message on the screen.
The exit status of a pipeline is the status of the last command in the pipeline. So in your case, it's the status of cut, not mysql.
You can use the PIPESTATUS array to get the exit status of other commands in the pipeline. However, this is tricky when the pipeline is in a command substitution, because you need PIPESTATUS from the subshell. See Pipe status after command substitution
If you don't want to see the database error message, you need to redirect stderr.
You need to check if the status is not 0. In the shell, 0 means success.
TABLES=$(mysql --skip-column-name -u $USER -pPASSWORD $DB -e "SHOW TABLES;" 2>/dev/null | grep -v '+' | cut -d' ' -f2; echo ": ${PIPESTATUS[0]}")
status=${TABLES##*: }
if [ $status -ne 0 ]
then
echo "There is something wrong with the arguments provided">&2
exit 2
else
# Remove the appended status
TABLES=${TABLES%:*}
TABLES=${TABLES%$'\n'}
fi

How can I execute MySQL commands line by line from bash and capture the output?

If there is an alternative to bash, I will appreciate it too.
I have a large dump of MySQL commands (over 10 GB)
When restoring the dump I get a few warnings and occasionally an error. I need to execute those commands and process all warnings and errors. And, preferibly to do it automatically.
mysql --show-warnings
tee logfile.log
source dump.sql
The logfile will contain many lines telling each command was successful, and will display some warnings, particulartly truncate colums. But the original file has tens of thousands of very large INSERTs, the log is not particularly helpful. Despite it requires some kind of supervised interaction. (I cannot program a crontab, for example.)
#!/bin/bash
echo "tee logfile.log" > script.sql
echo "source $1" > script.sql
mysql --show-warnings < script.sql > tmpfile.log 2>&1
cat tmpfile.log >> logfile.log
The tee command doesn't work in this batch environment. I can capture all the warnings, but I cannot figure out which command produced each warning.
So I came down with this small monstruosity:
#!/bin/bash
ERRFILE=$(basename "$0" .sh).err.log
LOGFILE=$(basename "$1" .sql).log
log_action() {
WARN=$(cat)
[ -z "$WARN" ] || echo -e "Line ${1}: ${WARN}\n${2}" >> "$LOGFILE"
}
echo 0 > "$ERRFILE"
log_error() {
ERNO=$(cat "$ERRFILE")
ERR=$(cat)
[ -z "$ERR" ] || echo -e "*** ERROR ***\nLine ${1}: ${ERR}\n${2}" >> "$LOGFILE"
(( ERNO++ ))
echo $ERNO > "$ERRFILE"
}
COUNT=0
COMMAND=''
echo -e "**** BEGIN $(date +%Y-%m-%d\ %H:%M:%S)\n" > "$LOGFILE"
exec 4> >(log_action $COUNT "$COMMAND")
exec 5> >(log_error $COUNT "$COMMAND")
exec 3> >(mysql --show-warnings >&4 2>&5)
while IFS='' read -r LINE || [[ -n "$line" ]]
do
(( COUNT++ ))
[ ${#LINE} -eq 0 ] && continue # discard blank lines
[ "${LINE:0:2}" = "--" ] && continue # discard comments
COMMAND+="$LINE" # build command
[ "${LINE: -1}" != ";" ] && continue # if not finnished keep building
echo $COMMAND >&3 # otherwise execute
COMMAND=''
done < "$1"
exec 3>$-
exec 5>$-
exec 4>$-
echo -e "**** END $(date +%Y-%m-%d\ %H:%M:%S)\n" >> "$LOGFILE"
ERRS=$(cat "$ERRFILE")
[ "ERRS" = 0 ] || echo "${ERRS} Errors." >&2
This scans the file at $1 and sends the commands to an open MySQL connection at &3. That part is working fine.
The capture of warnings and errors is not working though.
It only records the first error.
It only records the first warning.
I haven't find a good way to pass the line number $COUNT and offending command $COMMAND to the recording functions.
The only error is after the time stamps, and the only warning is after the error, which is not the chronology of the script.

How to parse json response in the shell script?

I am working with bash shell script. I need to execute an URL using shell script and then parse the json data coming from it.
This is my URL - http://localhost:8080/test_beat and the responses I can get after hitting the URL will be from either these two -
{"error": "error_message"}
{"success": "success_message"}
Below is my shell script which executes the URL using wget.
#!/bin/bash
DATA=$(wget -O - -q -t 1 http://localhost:8080/test_beat)
#grep $DATA for error and success key
Now I am not sure how to parse json response in $DATA and see whether the key is success or error. If the key is success, then I will print a message "success" and print $DATA value and exit out of the shell script with zero status code but if the key is error, then I will print "error" and print $DATA value and exit out of the shell script with non zero status code.
How can I parse json response and extract the key from it in shell script?
I don't want to install any library to do this since my JSON response is fixed and it will always be same as shown above so any simpler way is fine.
Update:-
Below is my final shell script -
#!/bin/bash
DATA=$(wget -O - -q -t 1 http://localhost:8080/tester)
echo $DATA
#grep $DATA for error and success key
IFS=\" read __ KEY __ MESSAGE __ <<< "$DATA"
case "$KEY" in
success)
exit 0
;;
error)
exit 1
;;
esac
Does this looks right?
If you are going to be using any more complicated json from the shell and you can install additional software, jq is going to be your friend.
So, for example, if you want to just extract the error message if present, then you can do this:
$ echo '{"error": "Some Error"}' | jq ".error"
"Some Error"
If you try this on the success case, it will do:
$echo '{"success": "Yay"}' | jq ".error"
null
The main advantage of the tool is simply that it fully understands json. So, no need for concern over corner cases and whatnot.
#!/bin/bash
IFS= read -d '' DATA < temp.txt ## Imitates your DATA=$(wget ...). Just replace it.
while IFS=\" read -ra LINE; do
case "${LINE[1]}" in
error)
# ERROR_MSG=${LINE[3]}
printf -v ERROR_MSG '%b' "${LINE[3]}"
;;
success)
# SUCCESS_MSG=${LINE[3]}
printf -v SUCCESS_MSG '%b' "${LINE[3]}"
;;
esac
done <<< "$DATA"
echo "$ERROR_MSG|$SUCCESS_MSG" ## Shows: error_message|success_message
* %b expands backslash escape sequences in the corresponding argument.
Update as I didn't really get the question at first. It should simply be:
IFS=\" read __ KEY __ MESSAGE __ <<< "$DATA"
[[ $KEY == success ]] ## Gives $? = 0 if true or else 1 if false.
And you can examine it further:
case "$KEY" in
success)
echo "Success message: $MESSAGE"
exit 0
;;
error)
echo "Error message: $MESSAGE"
exit 1
;;
esac
Of course similar obvious tests can be done with it:
if [[ $KEY == success ]]; then
echo "It was successful."
else
echo "It wasn't."
fi
From your last comment it can be simply done as
IFS=\" read __ KEY __ MESSAGE __ <<< "$DATA"
echo "$DATA" ## Your really need to show $DATA and not $MESSAGE right?
[[ $KEY == success ]]
exit ## Exits with code based from current $?. Not necessary if you're on the last line of the script.
You probably already have python installed, which has json parsing in the standard library. Python is not a great language for one-liners in shell scripts, but here is one way to use it:
#!/bin/bash
DATA=$(wget -O - -q -t 1 http://localhost:8080/test_beat)
if python -c '
import json, sys
exit(1 if "error" in json.loads(sys.stdin.read()) else 0)' <<<"$DATA"
then
echo "SUCCESS: $DATA"
else
echo "ERROR: $DATA"
exit 1
fi
Given:
that you don't want to use JSON libraries.
and that the response you're parsing is simple and the only thing you care about is the presence of substring "success", I suggest the following simplification:
#!/bin/bash
wget -O - -q -t 1 http://localhost:8080/tester | grep -F -q '"success"'
exit $?
-F tells grep to search for a fixed (literal) string.
-q tells grep to produce no output and instead only reflect via its exit code whether a match was found or not.
exit $? simply exits with grep's exit code ($? is a special variable that reflects the most recently executed command's exit code).
Note that if you all you care about is whether wget's output contains "success", the above pipeline will do - no need to capture wget's output in an aux. variable.

conditional statement in bash with mysql query

im trying to write a bash script that will do a mysql query and if the number of results is 1, do something. i cant get it to work though.
#!/bin/sh
file=`mysql -uroot -proot -e "select count(*) from MyTable.files where strFilename='file.txt'"`
if [[ $file == "count(*) 1" ]];
then
echo $file
else
echo $file
echo "no"
fi
i verified the query works. i keep getting this returned
count(*) 1
no
im not sure why but i think it might have something to do with the type of variable $file is. any ideas?
To prevent exposing your database credential in the script you can store them in the local .my.cnf file located in your home directory.
This technic will allow your script to work on any server without modification.
Path: /home/youruser/.my.cnf
Content:
[client]
user="root"
password="root"
host="localhost"
[mysql]
database="MyTable"
So, Renato code could be rewritten by following:
#!/bin/sh
file=`mysql -e "select count(*) as count from files where strFilename='file.txt'" | cut -d \t -f 2`
if [ $file == "1" ];
then
echo $file
else
echo $file
echo "no"
fi
I rewrote your script, it works now:
#!/bin/sh
file=`mysql -uroot -proot -e "select count(*) as count from MyTable.files where strFilename='file.txt'" | cut -d \t -f 2`
if [ $file == "1" ];
then
echo $file
else
echo $file
echo "no"
fi
I'm giving a better name to the count field, using 'cut' to split the mysql output into two fields and putting the content of the second field into $file. Then you can test $file for "1". Hope it helps you..
I'm guessing that isn't actually count(*) 1 but instead count(*)\n1 or something. echo $file will convert all the characters in IFS to a space, but == will distinguish between those whitespace characters. If this is the case, echo "$file" will give you a different result. (Notice the quotes.)