Does anyone can write a thread to teach me how to install Windows 2000, RH Linux, and FreeBSD unix in one machine step by step? Or someone's already done with this topic? (1 Reply)
hi, all,
i saw a syntax like this
usr/local/mpiexec -np 8 /home/XXXX/program_exe >& ./temp/out
the output will be put into ./temp/out.
I want to know the meaning of the operation symbol '>&'.
Thanks (3 Replies)
Hi Everyone,
i have a string 00:44:40
so:
$tmp=~ s/://gi;
$tmp=~s/({2})({2})({2})/$1*3600+$2*60+$3/e;
the output is 2680.
Any way to combine this two lines into a single line?
Thanks (4 Replies)
When trying to use backticks for system commands, is there a way to read the error messages if a command doesn't execute properly?
I have no problem getting the results if the command is properly executed.
Ex.
my @result = `dir`;
foreach my $line (@result) {
print "Result = $line";... (2 Replies)
Am actually am new to the linux operating system and knda wana knw more about it.Please could u help me with some commands so i can start with that first.Really need your help (5 Replies)
I am trying to enter a third column in this file, but the third column should that I call "Math" perform a some math calculations based on the value found in column #2.
Here is the input file:
Here is the desired output:
Output
GERk0203078$ Levir Math
Cotete_1... (5 Replies)
I can get my AIX servers to show up in SCOM but I'm struggling with running personal scripts and have the result of these scripts show up in SCOM.
I'm currently using BigBrother and I've written some scripts for BB. I would like to convert these scripts to something that can be used in SCOM.
... (0 Replies)
Hi All,
I want to display the distinct values in the file and for each distinct value how may occurance or there.
Test data:
test1.dat
20121105
20121105
20121105
20121105
20121106
20121106
20121106
20121105
I need to display the output like
Output (2 Replies)
Discussion started by: bbc17484
2 Replies
LEARN ABOUT FREEBSD
cat
CAT(1) BSD General Commands Manual CAT(1)NAME
cat -- concatenate and print files
SYNOPSIS
cat [-belnstuv] [file ...]
DESCRIPTION
The cat utility reads files sequentially, writing them to the standard output. The file operands are processed in command-line order. If
file is a single dash ('-') or absent, cat reads from the standard input. If file is a UNIX domain socket, cat connects to it and then reads
it until EOF. This complements the UNIX domain binding capability available in inetd(8).
The options are as follows:
-b Number the non-blank output lines, starting at 1.
-e Display non-printing characters (see the -v option), and display a dollar sign ('$') at the end of each line.
-l Set an exclusive advisory lock on the standard output file descriptor. This lock is set using fcntl(2) with the F_SETLKW command.
If the output file is already locked, cat will block until the lock is acquired.
-n Number the output lines, starting at 1.
-s Squeeze multiple adjacent empty lines, causing the output to be single spaced.
-t Display non-printing characters (see the -v option), and display tab characters as '^I'.
-u Disable output buffering.
-v Display non-printing characters so they are visible. Control characters print as '^X' for control-X; the delete character (octal
0177) prints as '^?'. Non-ASCII characters (with the high bit set) are printed as 'M-' (for meta) followed by the character for the
low 7 bits.
EXIT STATUS
The cat utility exits 0 on success, and >0 if an error occurs.
EXAMPLES
The command:
cat file1
will print the contents of file1 to the standard output.
The command:
cat file1 file2 > file3
will sequentially print the contents of file1 and file2 to the file file3, truncating file3 if it already exists. See the manual page for
your shell (e.g., sh(1)) for more information on redirection.
The command:
cat file1 - file2 - file3
will print the contents of file1, print data it receives from the standard input until it receives an EOF ('^D') character, print the con-
tents of file2, read and output contents of the standard input again, then finally output the contents of file3. Note that if the standard
input referred to a file, the second dash on the command-line would have no effect, since the entire contents of the file would have already
been read and printed by cat when it encountered the first '-' operand.
SEE ALSO head(1), more(1), pr(1), sh(1), tail(1), vis(1), zcat(1), fcntl(2), setbuf(3)
Rob Pike, "UNIX Style, or cat -v Considered Harmful", USENIX Summer Conference Proceedings, 1983.
STANDARDS
The cat utility is compliant with the IEEE Std 1003.2-1992 (``POSIX.2'') specification.
The flags [-belnstv] are extensions to the specification.
HISTORY
A cat utility appeared in Version 1 AT&T UNIX. Dennis Ritchie designed and wrote the first man page. It appears to have been cat(1).
BUGS
Because of the shell language mechanism used to perform output redirection, the command ``cat file1 file2 > file1'' will cause the original
data in file1 to be destroyed!
The cat utility does not recognize multibyte characters when the -t or -v option is in effect.
BSD January 29, 2013 BSD