How to extract logs between two time stamps

Question

I want to extract all logs between two timestamps. Some lines may not have the timestamp, but I want those lines also. In short, I want every line that falls under two time stamps. My log structure looks like:

[2014-04-07 23:59:58] CheckForCallAction [ERROR] Exception caught in +CheckForCallAction :: null
--Checking user--
Post
[2014-04-08 00:00:03] MobileAppRequestFilter [DEBUG] Action requested checkforcall

Suppose I want to extract everything between 2014-04-07 23:00 and 2014-04-08 02:00.

Please note the start time stamp or end time stamp may not be there in the log, but I want every line between these two time stamps.

Answer 1

You can use awk for this:

$ awk -F'[]]|[[]' \
  '$0 ~ /^\[/ && $2 >= "2014-04-07 23:00" { p=1 }
   $0 ~ /^\[/ && $2 >= "2014-04-08 02:00" { p=0 }
                                        p { print $0 }' log

Where:

• -F specifies the characters [ and ] as field separators using a regular expression
• $0 references a complete line
• $2 references the date field
• p is used as boolean variable that guards the actual printing
• $0 ~ /regex/ is true if regex matches $0
• >= is used for lexicographically comparing string (equivalent to e.g. strcmp())

Variations

The above command line implements right-open time interval matching. To get closed interval semantics just increment your right date, e.g.:

$ awk -F'[]]|[[]' \
  '$0 ~ /^\[/ && $2 >= "2014-04-07 23:00"    { p=1 }
   $0 ~ /^\[/ && $2 >= "2014-04-08 02:00:01" { p=0 }
                                           p { print $0 }' log

In case you want to match timestamps in another format you have to modify the $0 ~ /^\[/ sub-expression. Note that it used to ignore lines without any timestamps from print on/off logic.

For example for a timestamp format like YYYY-MM-DD HH24:MI:SS (without [] braces) you could modify the command like this:

$ awk \
  '$0 ~ /^[0-9]{4}-[0-9]{2}-[0-9]{2} [0-2][0-9]:[0-5][0-9]:[0-5][0-9]/
      {
        if ($1" "$2 >= "2014-04-07 23:00")     p=1;
        if ($1" "$2 >= "2014-04-08 02:00:01")  p=0;
      }
    p { print $0 }' log

(note that also the field separator is changed - to blank/non-blank transition, the default)

Answer 2

Check out dategrep at https://github.com/mdom/dategrep

Description:

dategrep searches the named input files for lines matching a date range and prints them to stdout.

If dategrep works on a seekable file, it can do a binary search to find the first and last line to print pretty efficiently. dategrep can also read from stdin if one the filename arguments is just a hyphen, but in this case it has to parse every single line which will be slower.

Usage examples:

dategrep --start "12:00" --end "12:15" --format "%b %d %H:%M:%S" syslog
dategrep --end "12:15" --format "%b %d %H:%M:%S" syslog
dategrep --last-minutes 5 --format "%b %d %H:%M:%S" syslog
dategrep --last-minutes 5 --format rsyslog syslog
cat syslog | dategrep --end "12:15" -

Although this limitation may make this unsuitable for your exact question:

At the moment dategrep will die as soon as it finds a line that is not parsable. In a future version this will be configurable.

Answer 3

One alternative to awk or a non-standard tool is to use GNU grep for its contextual greps. GNU's grep will let you specify the number of lines after a positive match to print with -A and the preceding lines to print with -B For example:

[davisja5@xxxxxxlp01 ~]$ cat test.txt
Ignore this line, please.
This one too while you're at it...
[2014-04-07 23:59:58] CheckForCallAction [ERROR] Exception caught in +CheckForCallAction :: null
--Checking user--
Post
[2014-04-08 00:00:03] MobileAppRequestFilter [DEBUG] Action requested checkforcall
we don't
want these lines.


[davisja5@xxxxxxlp01 ~]$ egrep "^\[2014-04-07 23:59:58\]" test.txt -A 10000 | egrep "^\[2014-04-08 00:00:03\]" -B 10000
[2014-04-07 23:59:58] CheckForCallAction [ERROR] Exception caught in +CheckForCallAction :: null
--Checking user--
Post
[2014-04-08 00:00:03] MobileAppRequestFilter [DEBUG] Action requested checkforcall

The above essentially tells grep to print the 10,000 lines that follow the line that matches the pattern you're wanting to start at, effectively making your output start where you're wanting it to and go until the end (hopefully) whereas the second egrep in the pipeline tells it to only print the line with the ending delimiter and the 10,000 lines before it. The end result of these two is starting where you're wanting and not going passed where you told it to stop.

10,000 is just a number I came up with, feel free to change it to a million if you think your output is going to be too long.

Answer 4

Well, it worked:

CMD=awk -v from=$Date1 -v to=$Date2

to count errors:

error_count=grep "error_message" ${logfile} | awk -F'[ .]' '{print $4}' | $CMD '$1>=from && $1<=to' | wc -l

here i used Date1 and Date2 as a parameter in which i stored the date at runtime. $4 gave me the timestamp in logs.

It was not taking date parameters directly in awk statement that's why i had to write CMD seperately (CMD is just kind of variable we can say)

Answer 5

Using sed :

#!/bin/bash

E_BADARGS=23

if [ $# -ne "3" ]
then
  echo "Usage: `basename $0` \"<start_date>\" \"<end_date>\" file"
  echo "NOTE:Make sure to put dates in between double quotes"
  exit $E_BADARGS
fi 

isDatePresent(){
        #check if given date exists in file.
        local date=$1
        local file=$2
        grep -q "$date" "$file"
        return $?

}

convertToEpoch(){
    #converts to epoch time
    local _date=$1
    local epoch_date=`date --date="$_date" +%s`
    echo $epoch_date
}

convertFromEpoch(){
    #converts to date/time format from epoch
    local epoch_date=$1
    local _date=`date  --date="@$epoch_date" +"%F %T"`
    echo $_date

}

getDates(){
        # collects all dates at beginning of lines in a file, converts them to epoch and returns a sequence of numbers
        local file="$1"
        local state="$2"
        local i=0
        local date_array=( )
        if [[ "$state" -eq "S" ]];then
            datelist=`cat "$file" | sed -r -e "s/^\[([^\[]+)\].*/\1/" | egrep  "^[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}"`
        elif [[ "$state" -eq "E" ]];then
            datelist=`tac "$file" | sed -r -e "s/^\[([^\[]+)\].*/\1/" | egrep  "^[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}"`

        else
            echo "Something went wrong while getting dates..." 1>&2
            exit 500
        fi

        while read _date
            do
                epoch_date=`convertToEpoch "$_date"`
                date_array[$i]=$epoch_date
                #echo "$_date" "$epoch_date" 1>&2

            (( i++ ))
            done<<<"$datelist"
        echo ${date_array[@]}   


}

findneighbours(){
    # search next best date if date is not in the file using recursivity
    IFS="$old_IFS"
    local elt=$1
    shift
    local state="$1"
    shift
    local -a array=( "$@" ) 

    index_pivot=`expr ${#array[@]} / 2`
    echo "#array="${#array[@]} ";array="${array[@]} ";index_pivot="$index_pivot 1>&2
    if [ "$index_pivot" -eq 1 -a ${#array[@]} -eq 2 ];then

        if [ "$state" == "E" ];then
            echo ${array[0]}
        elif [ "$state" == "S" ];then
            echo ${array[(( ${#array[@]} - 1 ))]} 
        else
            echo "State" $state "undefined" 1>&2
            exit 100
        fi

    else
        echo "elt with index_pivot="$index_pivot":"${array[$index_pivot]} 1>&2
        if [ $elt -lt ${array[$index_pivot]} ];then
            echo "elt is smaller than pivot" 1>&2
            array=( ${array[@]:0:(($index_pivot + 1)) } )
        else
            echo "elt is bigger than pivot" 1>&2
            array=( ${array[@]:$index_pivot:(( ${#array[@]} - 1 ))} ) 
        fi
        findneighbours "$elt" "$state" "${array[@]}"
    fi
}



findFirstDate(){
    local file="$1"
    echo "Looking for first date in file" 1>&2
    while read line
        do 
            echo "$line" | egrep -q "^\[[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}\]" &>/dev/null
            if [ "$?" -eq "0" ]
            then
                #echo "line=" "$line" 1>&2
                firstdate=`echo "$line" | sed -r -e "s/^\[([^\[]+)\].*/\1/"`
                echo "$firstdate"
                break
            else
                echo $? 1>&2
            fi
        done< <( cat "$file" )



}

findLastDate(){
    local file="$1"
    echo "Looking for last date in file" 1>&2
    while read line
        do 
            echo "$line" | egrep -q "^\[[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}\]" &>/dev/null
            if [ "$?" -eq "0" ]
            then
                #echo "line=" "$line" 1>&2
                lastdate=`echo "$line" | sed -r -e "s/^\[([^\[]+)\].*/\1/"`
                echo "$lastdate"
                break
            else
                echo $? 1>&2
            fi
        done< <( tac "$file" )


}

findBestDate(){

        IFS="$old_IFS"
        local initdate="$1"
        local file="$2"
        local state="$3"
        local first_elts="$4"
        local last_elts="$5"
        local date_array=( )
        local initdate_epoch=`convertToEpoch "$initdate"`   

        if [[ $initdate_epoch -lt $first_elt ]];then
            echo `convertFromEpoch "$first_elt"`
        elif [[ $initdate_epoch -gt $last_elt ]];then
            echo `convertFromEpoch "$last_elt"` 

        else
            date_array=( `getDates "$file" "$state"` )
            echo "date_array="${date_array[@]} 1>&2
            #first_elt=${date_array[0]}
            #last_elt=${date_array[(( ${#date_array[@]} - 1 ))]}

            echo `convertFromEpoch $(findneighbours "$initdate_epoch" "$state" "${date_array[@]}")`

        fi

}


main(){
    init_date_start="$1"
    init_date_end="$2"
    filename="$3"
    echo "problem start.." 1>&2
    date_array=( "$init_date_start","$init_date_end"  )
    flag_array=( 0 0 )
    i=0
    #echo "$IFS" | cat -vte
    old_IFS="$IFS"
    #changing separator to avoid whitespace issue in date/time format
    IFS=,
    for _date in ${date_array[@]}
    do
        #IFS="$old_IFS"
        #echo "$IFS" | cat -vte
        if isDatePresent "$_date" "$filename";then
            if [ "$i" -eq 0 ];then 
                echo "Starting date exists" 1>&2
                #echo "date_start=""$_date" 1>&2
                date_start="$_date"
            else
                echo "Ending date exists" 1>&2
                #echo "date_end=""$_date" 1>&2
                date_end="$_date"
            fi

        else
            if [ "$i" -eq 0 ];then 
                echo "start date $_date not found" 1>&2
            else
                echo "end date $_date not found" 1>&2
            fi
            flag_array[$i]=1
        fi
        #IFS=,
        (( i++ ))
    done

    IFS="$old_IFS"
    if [ ${flag_array[0]} -eq 1 -o ${flag_array[1]} -eq 1 ];then

        first_elt=`convertToEpoch "$(findFirstDate "$filename")"`
        last_elt=`convertToEpoch "$(findLastDate "$filename")"`
        border_dates_array=( "$first_elt","$last_elt" )

        #echo "first_elt=" $first_elt "last_elt=" $last_elt 1>&2
        i=0
        IFS=,
        for _date in ${date_array[@]}
        do
            if [ $i -eq 0 -a ${flag_array[$i]} -eq 1 ];then
                date_start=`findBestDate "$_date" "$filename" "S" "${border_dates_array[@]}"`
            elif [ $i -eq 1 -a ${flag_array[$i]} -eq 1 ];then
                date_end=`findBestDate "$_date" "$filename" "E" "${border_dates_array[@]}"`
            fi

            (( i++ ))
        done
    fi


    sed -r -n "/^\[${date_start}\]/,/^\[${date_end}\]/p" "$filename"

}


main "$1" "$2" "$3"

Copy this in a file. If you don't want to see debugging info, debugging is sent to stderr so just add "2>/dev/null"

Answer 6

I couldn't get the awk answer to work and found that sed can be used.

On https://www.unix.com/shell-programming-and-scripting/123623-pull-log-between-two-dates.html

sed -n '/12.Nov.2009:10:45:16/,/12.Nov.2009:10:45:16/p' infile

This prints all of the lines between the starting pattern and the ending pattern. I know it doesn't exactly answer the OPs question but I thought others might find the sed answer useful and potentially easier than using awk.

This solution doesn't handle this:

the start time stamp or end time stamp may not be there in the log, but I want every line between these two time stamps.

Answer 7

If anybody wants to get the logs within aparticular time range (maybe you want to get the logs within 5 min) you can do like shown below. It will fetch all the logs between the time range

For dynamic time range (e.g. you don't know the time range but need logs between last 5 min)

#!/bin/bash
LOG_FILE="./modsec.txt"
SEARCH_WORD="ModSecurity: Access denied"
START_TIME=$(date -d "5 minutes ago" "+%H:%M")
END_TIME=$(date "+%H:%M")

# using sed
sed -n "/"$START_TIME"/,/"$CURRENT_TIME"/p" "$LOG_FILE" | grep -w "$SEARCH_WORD"

For static time range (you know the time range):

sed -n "/hh:mm/,/hh:mm/p" "$LOG_FILE" | grep -w "$SEARCH_WORD"

You can replace the time range based on your timestamp.