How to display certain line of file only using head or tail in 1 command?
First month learning about the Linux terminal and it has been a challenge yet fun so far. We're learning by using a gameshell. I'm trying to display a certain line ( only allowed 1 command ) from a file only using the head or tail. I'm pretty about this answer:
However, it is not the good answer once I complete the gash check.
I've a major file which includes other files and now I wanna 'cut' the file in several minor parts....like
....
find / -name "*.tmp" >filea
wc -l filea >fileb
sed -e '1s/ filea//' fileb >filec
AMOUNT=`cat filec`
if ; then
cat file a |head -100l (ell) |tail -100l >filec
cat file a |head... (6 Replies)
I am new to UNIX......I have one file which contains thousnads of records with header and tailer.
Header
Record 1
Record 2
....
....
Last Record
Trailer
I want to concatenate Header and Trailer in the first line....now the output should look like this:
Header: Header value, Trailer:... (2 Replies)
Hi,
I have been given assignment of 30 scripts out of which I was able to solve many, I need help with few out of which one asks to imitate head and tail command of unix without using the head and tail commands. Problem is stated below:
Write an interactive shell script to imitate the head... (5 Replies)
Hi ,
1)i want to display specific line number using tail command.
e.g. display 10 line from end.
Please help...
2)Want to display line 10 to 15 (from end)using tail command) (2 Replies)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
view the 7th line of the program xxx.sh
2. Relevant commands, code, scripts, algorithms:
head command tail... (10 Replies)
Hi,
I want to read a live log file line by line and considering those line which are newly added to file
Below code I am using, which read line but as soon as it read new line from log file its starts processing from very first line of file.
tail -F /logs/COMMON-ERROR.log | while read... (11 Replies)
Discussion started by: ketanraut
11 Replies
LEARN ABOUT NETBSD
tail
TAIL(1) BSD General Commands Manual TAIL(1)NAME
tail -- display the last part of a file
SYNOPSIS
tail [-f | -F | -r] [-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
starting 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 is the same as the -f option, except that every five seconds tail will check to see if the file named on the command
line has been shortened or moved (it is considered moved if the inode or device number changes) and, if so, it will close the current
file, open the filename given, print out the entire contents, and continue to wait for more data to be appended. This option is used
to follow log files though rotation by newsyslog(8) or similar programs.
-n number
The location is number lines.
-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.
The tail utility exits 0 on success, and >0 if an error occurs.
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 -b, -r and -F
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 Version 7 AT&T UNIX.
BUGS
When using the -F option, tail will not detect a file truncation if, between the truncation and the next check of the file size, data written
to the file make it larger than the last known file size.
BSD June 6, 1993 BSD