What an limpid explaination ! It's clearer for me, thank you.
I have a particular case, when i have a gzip file like server.log.gz
I tried to use zcat in the script.
An error has occured. Fatal can't open zcat server.log.gz
What's the problem ?
Hi,
I know I can use touch and find's "! -newer" option to list files that are older than a specific time, but what is a good way to get a list of files that are over 12 hours old?
The log pruner will run throughout the day, twice an hour. So I can't easily use a cronjob touch command to generate... (1 Reply)
I'm looking to pull the last 24 hours of a log file.
Here's what I've got so far:
yesterday=$(TZ=$TZ+24 date +"%b %e %H:%M")
today=$(date +"%b %e %H:%M")
echo $yesterday $today
grep -E "^$yesterday|^$today" /var/adm/syslog/syslog.log
But that pulls everything from $yesterday from... (1 Reply)
Hi Frens,
I want to list some files from a directory, which contains "DONE" in their name, i am receiving files every minute. In this i want to list all the files which are newer than 6 hours but older than 3 hours, of current time
i dont want my list to contain the latest files which are ... (4 Replies)
Hi,
Good Afternoon!
I am writing this script on "sh" and have Variables as below.
#Time in hours ex: 09
JobTime=`echo $StartTime |awk '{print $2}'|cut -f1 -d':'`
SystemHours=`date +%H`
How can go 4 hours back for each variable in a day?
Another Question?
JobStat=`dsjob -report... (5 Replies)
stupid question im sure, but its frustrating
My cron jobs are off by 5 hours. My system time is right but all of my cron jobs are running approximately 5 hours late. Any idea why? (4 Replies)
I have a file that should cover a days worth of stats, at the beginning of each 15 minute report I have a unique header that looks like the below example. The "0000" and "0015" will change in the header line to show which 15 Minute interval the report is covering and of course from day to day the... (7 Replies)
Hi ,
We have around 22 logs , each has different entries. I have to automate this using shell script. The ideas which am sharing is given below
1) We use only TAIL -100 <location and name of the log> Command to check the logs.
2) We want to check whether the log was updated before 24... (13 Replies)
I want to parse a log file which i am grepping root user connection but is showing whole day and previous day detail as well.
First i want to see last 2 hours log file then after that i want to search particular string. Lets suppose right now its 5:00PM, So i want to see the log of 3:00PM to... (6 Replies)
Discussion started by: learnbash
6 Replies
LEARN ABOUT V7
grep
GREP(1) General Commands Manual GREP(1)NAME
grep, egrep, fgrep - search a file for a pattern
SYNOPSIS
grep [ option ] ... expression [ file ] ...
egrep [ option ] ... [ expression ] [ file ] ...
fgrep [ option ] ... [ strings ] [ file ]
DESCRIPTION
Commands of the grep family search the input files (standard input default) for lines matching a pattern. Normally, each line found is
copied to the standard output; unless the -h flag is used, the file name is shown if there is more than one input file.
Grep patterns are limited regular expressions in the style of ed(1); it uses a compact nondeterministic algorithm. Egrep patterns are full
regular expressions; it uses a fast deterministic algorithm that sometimes needs exponential space. Fgrep patterns are fixed strings; it
is fast and compact.
The following options are recognized.
-v All lines but those matching are printed.
-c Only a count of matching lines is printed.
-l The names of files with matching lines are listed (once) separated by newlines.
-n Each line is preceded by its line number in the file.
-b Each line is preceded by the block number on which it was found. This is sometimes useful in locating disk block numbers by con-
text.
-s No output is produced, only status.
-h Do not print filename headers with output lines.
-y Lower case letters in the pattern will also match upper case letters in the input (grep only).
-e expression
Same as a simple expression argument, but useful when the expression begins with a -.
-f file
The regular expression (egrep) or string list (fgrep) is taken from the file.
-x (Exact) only lines matched in their entirety are printed (fgrep only).
Care should be taken when using the characters $ * [ ^ | ? ' " ( ) and in the expression as they are also meaningful to the Shell. It is
safest to enclose the entire expression argument in single quotes ' '.
Fgrep searches for lines that contain one of the (newline-separated) strings.
Egrep accepts extended regular expressions. In the following description `character' excludes newline:
A followed by a single character matches that character.
The character ^ ($) matches the beginning (end) of a line.
A . matches any character.
A single character not otherwise endowed with special meaning matches that character.
A string enclosed in brackets [] matches any single character from the string. Ranges of ASCII character codes may be abbreviated
as in `a-z0-9'. A ] may occur only as the first character of the string. A literal - must be placed where it can't be mistaken as
a range indicator.
A regular expression followed by * (+, ?) matches a sequence of 0 or more (1 or more, 0 or 1) matches of the regular expression.
Two regular expressions concatenated match a match of the first followed by a match of the second.
Two regular expressions separated by | or newline match either a match for the first or a match for the second.
A regular expression enclosed in parentheses matches a match for the regular expression.
The order of precedence of operators at the same parenthesis level is [] then *+? then concatenation then | and newline.
SEE ALSO ed(1), sed(1), sh(1)DIAGNOSTICS
Exit status is 0 if any matches are found, 1 if none, 2 for syntax errors or inaccessible files.
BUGS
Ideally there should be only one grep, but we don't know a single algorithm that spans a wide enough range of space-time tradeoffs.
Lines are limited to 256 characters; longer lines are truncated.
GREP(1)