06-15-2014
awk last n lines of file
Just my second week working on awk I need a hint for the following tasks.
I want to limit my logfile from the very outset to 200 lines. All I do until now is
head -c 10K >> /home/uplog.txt | awk 'END{print NR " swap " NF$5; exit}' /home/uplog.txt;
After being read it shall print the very last record " some text " of the fifth field and right after that exit, due to the size of the file.
How can I set the limit to a certain number of lines?
My wiry selfmade logfile should be read only the last n lines, e.g. 10. I've been typing something like NR-1 but that gives just the line before the very last one. So how can I set a range like NR>=1&&NR<=5 or even more sophisticated /~^start !/,/~^stop !/ ?
If someone can give me a hint that would be great, thanks in advance.
10 More Discussions You Might Find Interesting
1. UNIX for Advanced & Expert Users
I have a file which is one big long line of text about 10Kb long.
Can someone provide a way using awk to introduce carriage returns every 40 chars in this file.
Any other solutions would also be welcome.
Thank you in advance. (5 Replies)
Discussion started by: martinbarretto
5 Replies
2. Shell Programming and Scripting
Hi there, I have a text file with several colums separated by "|;#" I need to search the file extracting all columns starting with the value of "1" or "2" saving in a separate file just the first 7 columns of each row maching the criteria, with replacement of the saparators in the nearly created... (4 Replies)
Discussion started by: capnino
4 Replies
3. UNIX for Dummies Questions & Answers
I have a file with 8 fields. I need the subtotals for fields 7 & 8 when field 5 changes.
cat wk1
01/02/2011/18AB/17/18/000000071/000000033
01/02/2011/18AB/17/18/000000164/000000021
01/02/2011/18AB/17/18/000000109/000000023
01/02/2011/28FB/04/04/000000000/000000000... (2 Replies)
Discussion started by: MS75001
2 Replies
4. Shell Programming and Scripting
Dear All,
a.txt
A 1 Z
A 1 ZZ
B 2 Y
B 2 AA
how can i use awk one line to achieve the result:
A Z|ZZ
B Y|AA
Thanks (5 Replies)
Discussion started by: jimmy_y
5 Replies
5. Shell Programming and Scripting
Hi,
Here i have to check first record $3 $4 with second record $1 $2 respectively. If match found, then check first record $2 == second record $4 , if it equals , then reduce two records to single record like as desired output.
Input_file
1 1 2 1
2 1 3 1
3 1 4 1
3 1 3 2
desired... (3 Replies)
Discussion started by: vasanth.vadalur
3 Replies
6. Shell Programming and Scripting
Hi,
how do i read a file using awk for a given no of line?
e.g
1. read only first 50 line.
2. read starting from line 20 to line 60..
thanks in advance.
-alva (8 Replies)
Discussion started by: alvagenesis
8 Replies
7. Shell Programming and Scripting
I want to count lines of a file using AWK (only) and not in the END part like this awk 'END{print FNR}' because I want to use it.
Does anyone know of a way?
Thanks a lot. (7 Replies)
Discussion started by: guitarist684
7 Replies
8. Shell Programming and Scripting
Sorry for the weird title but i have the following problem.
We have several files which have between 10000 and about 500000 lines in them. From these files we want to remove lines which contain a pattern which is located in another file (around 20000 lines, all EAN codes). We also want to get... (28 Replies)
Discussion started by: SDohmen
28 Replies
9. Shell Programming and Scripting
The output of an awk script is the below file. Line 1,3 that starts with the Ion... need to be under line 2,4 that starts with R_. The awk runs but no output results. Thank you :).
file
IonXpress_007 MEV37
R_2016_09_20_12_47_36_user_S5-00580-7-Medexome
IonXpress_007 MEV40... (6 Replies)
Discussion started by: cmccabe
6 Replies
10. UNIX for Beginners Questions & Answers
The awk below executes and is close (producing the first 4 columns in desired). However, when I add the sum of $7, I get nothing returned. Basically, I am trying to combine all the matching $4 in f1 and output them with the average of $7 in each match. Thank you :).
f1
... (2 Replies)
Discussion started by: cmccabe
2 Replies
LEARN ABOUT LINUX
cachefslog
cachefslog(1M) System Administration Commands cachefslog(1M)
NAME
cachefslog - Cache File System logging
SYNOPSIS
cachefslog [-f logfile | -h] cachefs_mount_point
DESCRIPTION
The cachefslog command displays where CacheFS statistics are being logged. Optionally, it sets where CacheFS statistics are being logged,
or it halts logging for a cache specified by cachefs_mount_point. The cachefs_mount_point argument is a mount point of a cache file system.
All file systems cached under the same cache as cachefs_mount_point will be logged.
OPTIONS
The following options are supported. You must be super-user to use the -f and -h options.
-f logfile Specify the log file to be used.
-h Halt logging.
OPERANDS
cachefs_mount_point A mount point of a cache file system.
USAGE
See largefile(5) for the description of the behavior of cachefslog when encountering files greater than or equal to 2 Gbyte ( 2**31 bytes).
EXAMPLES
Example 1: Checking the Logging of a directory.
The example below checks if the directory /home/sam is being logged:
example% cachefslog /home/sam
not logged: /home/sam
Example 2: Changing the logfile.
The example below changes the logfile of /home/sam to /var/tmp/samlog:
example# cachefslog -f /var/tmp/samlog /home/sam
/var/tmp/samlog: /home/sam
Example 3: Verifying the change of a logfile.
The example below verifies the change of the previous example:
example% cachefslog /home/sam
/var/tmp/samlog: /home/sam
Example 4: Halting the logging of a directory.
The example below halts logging for the /home/sam directory:
example# cachefslog -h /home/sam
not logged: /home/sam
EXIT STATUS
The following exit values are returned:
0 success
non-zero an error has occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO
cachefsstat(1M), cachefswssize(1M), cfsadmin(1M), attributes(5), largefile(5)
DIAGNOSTICS
Invalid path It is illegal to specify a path within a cache file system.
SunOS 5.10 7 Feb 1997 cachefslog(1M)