I know how to read and write if i have a forked process with only one child. However what is involved with reading and writing with many forked processes. Say one parent that forks 5 children, and needs to communicate with all 5 in half duplex.
int temp, counter=0;
do{
pipe(temp);
... (5 Replies)
OK... I'm fairly new to unix having the admin handed to me on a platter w/almost no training.
However, being a programmer, I do pick up things fairly easily, but this one is getting the best of me.
I have a unix server that runs multiple versions of the same ERP system, hand crafted for our... (1 Reply)
Morning All,
Quite a simple one this, I hope. What I want to do is to re-write the first line of a file before it's sent to print. The line will be blank initially, and I want to insert some text. The operation can either be done on the file itself (modifying the file on disk), OR in a... (2 Replies)
I want to try the unix pipe, the command is like this:
echo new | find .
the standard output of the echo should be "new", then I guess find command will use this output as input to find the file named "new". But the output is all the file names in my current dir, the last line is "echo: write... (5 Replies)
Hi -- I'm looking to write to a file after piping output from tail -f through to grep:
#write to a file for all lines with "searchtext" within in error_log:
Expand|Select|Wrap|Line Numbers
tail -f /var/error_log | grep searchtext > output.txt
The above command... (2 Replies)
The "write failed: Broken pipe" message is reported by the file sending PC which run my writed network device driver while 500MB or 900MB is sended!
What does the message mean? Does this mean there is a bug in my driver?
li,kunlun (11 Replies)
Hi friends,
I have a file where I should search for a string and get the rest of the line but without the delimiter using awk.
for example I have the series of string in a file:
input_string.txt
bbb
ccc
aaa
and the mapping file looks like this.
mapping.txt
aaa|12
bbb|23
ccc|43... (11 Replies)
Sed command to replace a line in a file using line number from the output of a pipe.
Is it possible to replace a whole line piped from someother command into a file at paritcular line...
here is some basic execution flow..
the line number is 412
lineNo=412
Now i have a line... (1 Reply)
I am trying to keep variables in a file.
if I have all variables at the same time, I can write them all like below.
echo $var1","$var2","$var3
But, these variables are being calculated at different times then they are lost
so I want to keep them in a file seperated by "," .
echo... (5 Replies)
I have a file as below
Emp1|FirstName|MiddleName|LastName|Address|Pincode|PhoneNumber
1234|FirstName1|MiddleName2|LastName3| Add1 || ADD2|123|000000000
2345|FirstName2|MiddleName3|LastName4|
Add1 || ADD2|
234|000000000
OUTPUT :
... (1 Reply)
Discussion started by: styris
1 Replies
LEARN ABOUT FREEBSD
uname
UNAME(1) BSD General Commands Manual UNAME(1)NAME
uname -- display information about the system
SYNOPSIS
uname [-aiKmnoprsUv]
DESCRIPTION
The uname command writes the name of the operating system implementation to standard output. When options are specified, strings represent-
ing one or more system characteristics are written to standard output.
The options are as follows:
-a Behave as though the options -m, -n, -r, -s, and -v were specified.
-i Write the kernel ident to standard output.
-K Write the FreeBSD version of the kernel.
-m Write the type of the current hardware platform to standard output.
-n Write the name of the system to standard output.
-o This is a synonym for the -s option, for compatibility with other systems.
-p Write the type of the machine processor architecture to standard output.
-r Write the current release level of the operating system to standard output.
-s Write the name of the operating system implementation to standard output.
-U Write the FreeBSD version of the user environment.
-v Write the version level of this release of the operating system to standard output.
If the -a flag is specified, or multiple flags are specified, all output is written on a single line, separated by spaces.
The -K and -U flags are intended to be used for fine grain differentiation of incremental FreeBSD development and user visible changes.
ENVIRONMENT
An environment variable composed of the string UNAME_ followed by any flag to the uname utility (except for -a) will allow the corresponding
data to be set to the contents of the environment variable.
EXIT STATUS
The uname utility exits 0 on success, and >0 if an error occurs.
SEE ALSO feature_present(3), getosreldate(3), sysctl(3), uname(3), sysctl(8)STANDARDS
The uname command is expected to conform to the IEEE Std 1003.2 (``POSIX.2'') specification.
HISTORY
The uname command appeared in PWB UNIX.
The -K and -U extension flags appeared in FreeBSD 10.0.
BSD November 20, 2013 BSD