Hi All,
I have been working on awk and arrays. I have this small script:
cat maillog*|awk -F: '$2=="SMTP-Accept" && $5~/string/ {lastdate=substr($1,1,8); internaluser=$5; v++} END {for (j in v) {print lastdate, v, j}'| sort>> mail.list
This gives me the number of mails users are getting. ... (1 Reply)
Been struggling with a problem, I have been trying to do this in awk, but am unable to figure this out, I think arrays have to be used, but unsure how to accomplish this.
I have a input file that looks like this:
141;ny;y;g
789;ct;e;e
23;ny;n;u
45;nj;e;u
216;ny;y;u
7;ny;e;e
1456;ny;e;g... (3 Replies)
Guys,
OK so i have been trying figure this all all day, i guess its a pretty easy way to do it.
Right, so i have to column of data which i have gotten from one huge piece of data. What i would like to do is to put both of these into one array using awk. Is this possible??
If so could... (1 Reply)
Hi, I've written the following code to manipulate the first 40 lines of a data file into my desired order:
#!/bin/awk -f
{ if (NR<=(4)){
a=a$0" "}
else { if ((NR >= (5)) && (NR <= (13))) {
b=b$0" " }
else {if ((NR >= (14)) && (NR <= (25))){
c=c$0" "}
... (5 Replies)
Hi,
I have spent the afternoon trawling Google, Unix.com and Unix in a Nutshell for information on how awk arrays work, and I'm not really getting too far.
I ahve a batch of code that I am pretty sure can be better managed using awk, but I'm not sure how to use awk arrays to do what I'm... (1 Reply)
Hi,
I have the following data in a file for example:
Name="Fred","Bob","Peterson","Susan","Weseley"
Age="24","30","28","23","45"
Study="English","Engineering","Physics","Maths","Psychology"
Code="0","0","1","1","0"
Name="Fred2","Bob2","Peterson2","Susan2","Weseley2"... (14 Replies)
Hi
Can someone please explain the logic of awk arrays. I have been doing some reading but I dont understand this:
#!/usr/bin/gawk -f
{
arr++;
}
end
{
for(i in arr)
{
print arr,i
}
}
As I understand arr refs the arrays index, so while $2 is a string that cant... (2 Replies)
Hi, buddies
I am new to shell scripting and trying to solve a problem. I read about arrays in awk that they are quite powerful and are associative in nature.
Awk Gurus Please help!
I have a file:
Id1 pp1 0t4 pp8 xy2
Id43 009y black
Id6 red xy2
Id12 new pp1 black
I have... (5 Replies)
I'm a little stuck and would be grateful of some advice!
I have three files, two of which contain reference data that I want to add to a line of output in the third file. I can't seem to get awk to print array contents as I would expect.
The input files are:
# Input file
AAA,OAA,0313... (2 Replies)
Discussion started by: maccas17
2 Replies
LEARN ABOUT FREEBSD
tail
TAIL(1) BSD General Commands Manual TAIL(1)NAME
tail -- display the last part of a file
SYNOPSIS
tail [-F | -f | -r] [-q] [-b number | -c number | -n number] [file ...]
DESCRIPTION
The tail utility displays the contents of file or, by default, its standard input, to the standard output.
The display begins at a byte, line or 512-byte block location in the input. Numbers having a leading plus ('+') sign are relative to the
beginning of the input, for example, ``-c +2'' starts the display at the second byte of the input. Numbers having a leading minus ('-') sign
or no explicit sign are relative to the end of the input, for example, ``-n 2'' displays the last two lines of the input. The default start-
ing location is ``-n 10'', or the last 10 lines of the input.
The options are as follows:
-b number
The location is number 512-byte blocks.
-c number
The location is number bytes.
-f The -f option causes tail to not stop when end of file is reached, but rather to wait for additional data to be appended to the
input. The -f option is ignored if the standard input is a pipe, but not if it is a FIFO.
-F The -F option implies the -f option, but tail will also check to see if the file being followed has been renamed or rotated. The
file is closed and reopened when tail detects that the filename being read from has a new inode number.
If the file being followed does not (yet) exist or if it is removed, tail will keep looking and will display the file from the begin-
ning if and when it is created.
The -F option is the same as the -f option if reading from standard input rather than a file.
-n number
The location is number lines.
-q Suppresses printing of headers when multiple files are being examined.
-r The -r option causes the input to be displayed in reverse order, by line. Additionally, this option changes the meaning of the -b,
-c and -n options. When the -r option is specified, these options specify the number of bytes, lines or 512-byte blocks to display,
instead of the bytes, lines or blocks from the beginning or end of the input from which to begin the display. The default for the -r
option is to display all of the input.
If more than a single file is specified, each file is preceded by a header consisting of the string ``==> XXX <=='' where XXX is the name of
the file unless -q flag is specified.
EXIT STATUS
The tail utility exits 0 on success, and >0 if an error occurs.
EXAMPLES
To display the last 500 lines of the file foo:
$ tail -n 500 foo
Keep /var/log/messages open, displaying to the standard output anything appended to the file:
$ tail -f /var/log/messages
SEE ALSO cat(1), head(1), sed(1)STANDARDS
The tail utility is expected to be a superset of the IEEE Std 1003.2-1992 (``POSIX.2'') specification. In particular, the -F, -b and -r
options are extensions to that standard.
The historic command line syntax of tail is supported by this implementation. The only difference between this implementation and historic
versions of tail, once the command line syntax translation has been done, is that the -b, -c and -n options modify the -r option, i.e., ``-r
-c 4'' displays the last 4 characters of the last line of the input, while the historic tail (using the historic syntax ``-4cr'') would
ignore the -c option and display the last 4 lines of the input.
HISTORY
A tail command appeared in PWB UNIX.
BSD March 16, 2013 BSD