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Full Discussion: awk last n lines of file
Top Forums Shell Programming and Scripting awk last n lines of file Post 302905870 by 1in10 on Sunday 15th of June 2014 05:47:32 PM
Old 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.
 

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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)
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