Creating a file inside a script

Shell Programming and Scripting
1

Hi,

How can I create a file inside a script. The thing is that, I have to create the file inside the script and it will be acting as a log file the script.Whenever I execute the script the file has to be created and the output has to be directed into that file.

Tahnks in advance

2

You can do something like this.

#! /bin/ksh
[ ! -f "$0.log" ] && > $0.log

function log
{
  echo "$@" >> "$0.log"
}

Where ever you want to log the output, invoke the function as

log "Value is $value"
3

Hi ,
There are many was to create any file. Since your requirement is to create a file for keeping information log it would be advisable to have same name as the script name.

to create a new file use any one of the following :

> file_name
echo '' > filename

for appending any thing you can use " >> filename ".

Below is the sample code which would help you creating your own script.

script_name=$(basename "$0")
base_file_name=`echo $script_name | cut -f 1 -d "."`
logfile=${base_file_name}.log

echo " Started executing ${script_name} at `date` \n > ${logfile}

echo "Start appening msg to the file like this " >> ${logfile}

-Manish Jha.

4

Hi.

Thanks. I got it. But I have a script that has defined a log file like this.

The name of the script is verify.sh
Inside the script there is some thing like this.
LOG=/usr/verify
TDATE=`date "+%m%d%y"$$`
LOGFILE=$LOG.$TDATE.

and inside the script it has been written as
echo "This is to verify" | tee -a $LOGFILE.

I understood that for every run this script will generate the mog file with the date appended to it. But I am not getting to know whether I have to create the file before running the script or the script will itself create the file. If I run the script as it is, it doesnt create the file.

Please put some light on how to run this script.

Thanks in advance.

5

It will create the file if it doesnt exist. From info tee

   If a file being written to does not already exist, it is created.
If a file being written to already exists, the data it previously
contained is overwritten unless the `-a' option is used.
6

The thing is that Its not creating the file if the file doesnt exist.

7

We cant say what is wrong without seeing the script.

Anyway, you can use add this line as well.

[ ! -f "$LOGNAME" ] &&  > "$LOGNAME"
8

This is the script:

DEFINE_ENV_VAR()
{
. /usr/dacscan/bin/DSCANenv
LOG=/dacscan/words/shdsl_mrp_verify_eqpt
DEFINE_ENV_VAR()
{
. /usr/dacscan/bin/DSCANenv
LOG=/dacscan/words/shdsl_mrp_verify_eqpt
ORACLE_HOME=/opt/oracle
ORACLE_SID=S
export ORACLE_HOME
export ORACLE_SID
TDATE=`date "+%m%d%y"$$`
DEFINE_ENV_VAR()
{
. /usr/dacscan/bin/DSCANenv
LOG=/dacscan/words/shdsl_mrp_verify_eqpt
ORACLE_HOME=/opt/oracle
ORACLE_SID=S
export ORACLE_HOME
export ORACLE_SID
TDATE=`date "+%m%d%y"$$`
LOGFILE=$log.$TDATE
}
user=`echo $LOGNAME`
if [ $user != dacscan ]
then
echo "Please login as 'dacscan' to run this tool" > $LOGFILE
exit 1
else
echo "U r a valid user and now the check for single instance is going on" | tee -a $LOGFILE
echo "U r user validation is successful"
fi

if [ ! -f /tmp/shdsl_mrp_verify_eqpt.tmp ]
then
ps -ef | grep shdsl_mrp_verify_eqpt.sh | awk '{print $8}' > /tmp/shdsl_mrp_verify_eqpt.tmp
else
echo "Another instance of the tool is already running. Only one instance of the tool can be run at a given point of time" | tee -a $LOGFILE
echo "Cannot run the tool as already another instance of the tool is running"
exit
fi

Create_Proc()
{
create=`sqlplus -s dacscan/mnc <<!
set serveroutput on;
start shdsl_mrp_verify_eqpt.sql;
!`
if [[ $(echo $create | grep "ORA-") != "" ]]
then
echo "Error occured while creating the procedure. Check the Activity log file for further details" | tee -a $LOGFILE
rm /tmp/shdsl_mrp_verify_eqpt.tmp
exit 1
fi
}

Run_Proc()
{
status=`sqlplus -s dacscan/mnc <<!
set serveroutput on;
spool shdsl_mrp_verify_eqpt;
exec EQPT_VERIFY;
spool off;
!`
if (($?!=0))
then
echo "Unable to connect to oracle for running/executing the procedure" |tee -a $LOGFILE
rm /tmp/shdsl_mrp_verify_eqpt.tmp
exit 1
elif [[ $(echo $status | grep "ORA-") != "" ]]
then
echo "Error occured while executing the procedure" | tee -a $LOGFILE
rm /tmp/shdsl_mrp_verify_eqpt.tmp
exit 1
fi
}
rm /tmp/shdsl_mrp_verify_eqpt.tmp
DEFINE_ENV_VAR
Create_Proc
Run_Proc

Now tell me what do I have to do.

Thanks in advance

9

I assume your script starts like this and not as shown above.

DEFINE_ENV_VAR()
{
. /usr/dacscan/bin/DSCANenv
LOG=/dacscan/words/shdsl_mrp_verify_eqpt
ORACLE_HOME=/opt/oracle
ORACLE_SID=S
export ORACLE_HOME
export ORACLE_SID
TDATE=`date "+%m%d%y"$$`
LOGFILE=$log.$TDATE
}
user=`echo $LOGNAME`
if [ $user != dacscan ]
then
echo "Please login as 'dacscan' to run this tool" > $LOGFILE
exit 1
else
echo "U r a valid user and now the check for single instance is going on" | tee -a $LOGFILE
echo "U r user validation is successful"
fi

if [ ! -f /tmp/shdsl_mrp_verify_eqpt.tmp ]
then
ps -ef | grep shdsl_mrp_verify_eqpt.sh | awk '{print $8}' > /tmp/shdsl_mrp_verify_eqpt.tmp
else
echo "Another instance of the tool is already running. Only one instance of the tool can be run at a given point of time" | tee -a $LOGFILE
echo "Cannot run the tool as already another instance of the tool is running"
exit
fi

Create_Proc()
{
create=`sqlplus -s dacscan/mnc <<!
set serveroutput on;
start shdsl_mrp_verify_eqpt.sql;
!`
if [[ $(echo $create | grep "ORA-") != "" ]]
then
echo "Error occured while creating the procedure. Check the Activity log file for further details" | tee -a $LOGFILE
rm /tmp/shdsl_mrp_verify_eqpt.tmp
exit 1
fi
}

Run_Proc()
{
status=`sqlplus -s dacscan/mnc <<!
set serveroutput on;
spool shdsl_mrp_verify_eqpt;
exec EQPT_VERIFY;
spool off;
!`
if (($?!=0))
then
echo "Unable to connect to oracle for running/executing the procedure" |tee -a $LOGFILE
rm /tmp/shdsl_mrp_verify_eqpt.tmp
exit 1
elif [[ $(echo $status | grep "ORA-") != "" ]]
then
echo "Error occured while executing the procedure" | tee -a $LOGFILE
rm /tmp/shdsl_mrp_verify_eqpt.tmp
exit 1
fi
}
rm /tmp/shdsl_mrp_verify_eqpt.tmp
DEFINE_ENV_VAR
Create_Proc
Run_Proc

Please put your code within code tags for easy reading.

10

Yeah,
you are right. Actually I made a mistake while pasting it here. But I just want to know where am I going wrong as the file doesnt get created.

11

These line

echo "Please login as 'dacscan' to run this tool" > $LOGFILE
exit 1
else
echo "U r a valid user and now the check for single instance is going on" | tee -a $LOGFILE

will never go into $LOGFILE. Because, they appear before the invocation of DEFINE_ENV_VAR. $LOGFILE doesnt have a name till DEFINE_ENV_VAR is called.

12

Exactly. Just now I changed it and now its working fine. Thanks a lot.