03-30-2013
The assignment directions are not "shit".
The directions are actually very good.
But you cannot finish the assignment unless you understand what a "pipe" is, and what "who" is. You can easily figure that out on your own, with a little research and experimentation.
Did your course mention "pipe" before? If not, you could look for pipe on wikipedia, as used in the computer sense. And think about what "who" might be? Is there a file on your computer called "who"? If not, then what's the other possibility about "who"? Again, you could even find the answer on wikipedia.
Keep at it. I would not email your teacher yet.
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hello all,
I have a test file that has the format:
.....
O
3.694950 -.895050 1.480000
O
5.485050 .895050 1.480000
Ti
-4.590000 4.590000 2.960000
Ti
-2.295000 ... (5 Replies)
Discussion started by: aarondesk
5 Replies
2. Shell Programming and Scripting
hello folks
i have a file that have data like
/test/aa/123
/test/aa/xyz
/test/bb/xyz
/test/bb/123
in above lines i just wants to grep "aa" and "bb".
Thanks,
Bash (4 Replies)
Discussion started by: learnbash
4 Replies
3. Shell Programming and Scripting
can someone help me in the awk part...little confuse on that part.
The problem is this: what input each utility gets and what it does with data and what output is provides to the next utility)
history | awk '{a++}END{for(i in a){print a " " i}}' | sort -rn | grep '^'
Thanks (4 Replies)
Discussion started by: Learnerabc
4 Replies
4. Shell Programming and Scripting
Hi Expert,
Kindly request for your expertise in this matter.
I have below output:
12.125.124.173,xx1.common.com
12.125.124.174,xx2.common.com
12.125.124.175,xx3.common.com
12.125.124.176,
12.125.124.177,
12.125.124.178,
12.125.124.179,xx4.common.com
12.125.124.180,xx5.common.com... (8 Replies)
Discussion started by: regmaster
8 Replies
5. Programming
for example, I have a text file in random content inside, maybe something like this.
234234
54654
123134
467456
24234234
7867867
23424
568567if I run this command
cat "filename.txt" | sort -n | grep "^467456$" -A 1 -B 1the result is
234234
467456
568567is it possible to do this command... (2 Replies)
Discussion started by: 14th
2 Replies
6. Shell Programming and Scripting
Pseudo name=hdiskpower54
Symmetrix ID=000190101757
Logical device ID=0601
state=alive; policy=SymmOpt; priority=0; queued-IOs=0
==============================================================================
---------------- Host --------------- - Stor - -- I/O Path - -- Stats ---
### HW... (7 Replies)
Discussion started by: Daniel Gate
7 Replies
7. Shell Programming and Scripting
Hi,
Trying to sort grep result based on timestamp of the filename.
I have the following result and want to sort them on timestampgrep -i 'ERROR' *log*2013*
s_m_xxx_xxx_xxx_xxx_xxxx.log.20130906092431:TRANSF_1_1_1> DBG_21216 Finished transformations for Source Qualifier . Total errors ... (5 Replies)
Discussion started by: bobbygsk
5 Replies
8. Homework & Coursework Questions
1. The problem statement, all variables and given/known data:
So i'll probably get told off for this but I have a few problems and rather than clog up the whole forum I'll post them here. Please bare in mind I am a complete novice when it comes to all this and so if you help please treat me like a... (4 Replies)
Discussion started by: jamesb18
4 Replies
9. Homework & Coursework Questions
1. The problem statement, all variables and given/known data:
Please bare in mind I am a complete novice to this and have very very basic knowledge so please keep any answers as simple as possible and explain in terms I will understand ahha :):)
I have a text file of names and test scores... (1 Reply)
Discussion started by: jamesb18
1 Replies
10. Shell Programming and Scripting
Hi Gurus,
I have two big files. I need to compare the different. currently, I am using
sort file1 > file1_temp;
sort file2 > file2_tmp
diff file1_tmp file2_tmp
I can use command
grep -v -f file1 file2
just wondering which way is fast to compare two big files.
Thanks... (4 Replies)
Discussion started by: ken6503
4 Replies
PIPE(2) System Calls Manual PIPE(2)
NAME
pipe - create an interprocess channel
SYNOPSIS
pipe(fildes)
int fildes[2];
DESCRIPTION
The pipe system call creates an I/O mechanism called a pipe. The file descriptors returned can be used in read and write operations. When
the pipe is written using the descriptor fildes[1] up to 4096 bytes of data are buffered before the writing process is suspended. A read
using the descriptor fildes[0] will pick up the data. Writes with a count of 4096 bytes or less are atomic; no other process can inter-
sperse data.
It is assumed that after the pipe has been set up, two (or more) cooperating processes (created by subsequent fork calls) will pass data
through the pipe with read and write calls.
The Shell has a syntax to set up a linear array of processes connected by pipes.
Read calls on an empty pipe (no buffered data) with only one end (all write file descriptors closed) returns an end-of-file.
SEE ALSO
sh(1), read(2), write(2), fork(2)
DIAGNOSTICS
The function value zero is returned if the pipe was created; -1 if too many files are already open. A signal is generated if a write on a
pipe with only one end is attempted.
BUGS
Should more than 4096 bytes be necessary in any pipe among a loop of processes, deadlock will occur.
ASSEMBLER
(pipe = 42.)
sys pipe
(read file descriptor in r0)
(write file descriptor in r1)
PIPE(2)