What exactly are you trying to do? Looks like you want to use pipes to communicate between the parent and child process. Standard output (stdout) of the parent process (ls) goes to the pipe which becomes the standard input (stdin) of the child process (sort). stdout of the child process...sort in this case...goes to a file.
Code:
ls | sort > file.out
Or are you sending the stdout of the parent process to a file which then becomes the stdin of the child process. Or if it's neither of the above. Be specific as to the one that best fits your needs.
Code:
ls > file.out
sort < file.out
Last edited by Yogesh Sawant; 02-26-2010 at 01:14 PM..
Reason: added code tags
Hi All.
I have the following simple shell program.
It reads a number from the "/user/amit/bldno";
for example: file "bldno" contains value "100"
After execution of the program the content should change to 101.
---------
#!/usr/bin/tcsh
V= `cat /user/amit/bldno`
echo $V
`rm -rf ... (1 Reply)
if test -z "$1"
then echo "you must give a filename or filepath"
else path=`dirname $1`
f_name =`basename $1`
if path="."
then path=`pwd`
fi
fi
cat $f_name $path >> index.txt
The only problem I am encountering with this is writing $path to index.txt
Keeps going gaga:
cat:... (1 Reply)
Hi All
I am new to C and trying to write a code to get a file as an output.
My text file should look like:
<var1>tab<var2>tab<var3>...upto the elements in an array
<varb1>tab<varb2>tab<varb3>...upto the elements in an array
Can someone please guide me how to write the code or a sample... (3 Replies)
Need to develop a unix shell script for the below requirement and I need your assistance:
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Help needed...
Can you tell me how to compare the last two couple entries in a file and print their result in new file..:confused:
I have one file
Check1.txt
\abc1 12345
\abc2 12327
\abc1 12345
\abc2 12330
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I am looking to do a ls on a folder and have the output of the ls be structured so that is is modificaiton date, file name with the date in a format that is compatible with mysql. I am trying to build a table that stores the last modification date of certain files so I can display it on some web... (4 Replies)
Hi
I am trying to extract information out of a file but keep getting grep cant open errors
the code is below:
#bash
#extract orders with blank address details
#
# obtain the current date
# set today to the current date ccyymmdd format
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echo... (8 Replies)
Hi All,
We have a Unix program in oracle when we run the program this connects to specified ftp and will get the file into local server.
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Could anyone please help me... (2 Replies)
Hi,
I have 1000 files names data1.txt through data1000.txt inside a folder. I want to write a script that will take each first line from the files and write them as output into a new file. How do I go about doing that? Thanks! (2 Replies)
Hello ,
I have comma delimited file with over 20 fileds that i need to do some validations on. I have to check if certain fields are null and then write the line containing the null field into a new file and then delete the line from the current file.
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Discussion started by: goddevil
2 Replies
LEARN ABOUT REDHAT
fork
FORK(2) Linux Programmer's Manual FORK(2)NAME
fork - create a child process
SYNOPSIS
#include <sys/types.h>
#include <unistd.h>
pid_t fork(void);
DESCRIPTION
fork creates a child process that differs from the parent process only in its PID and PPID, and in the fact that resource utilizations are
set to 0. File locks and pending signals are not inherited.
Under Linux, fork is implemented using copy-on-write pages, so the only penalty incurred by fork is the time and memory required to dupli-
cate the parent's page tables, and to create a unique task structure for the child.
RETURN VALUE
On success, the PID of the child process is returned in the parent's thread of execution, and a 0 is returned in the child's thread of exe-
cution. On failure, a -1 will be returned in the parent's context, no child process will be created, and errno will be set appropriately.
ERRORS
EAGAIN fork cannot allocate sufficient memory to copy the parent's page tables and allocate a task structure for the child.
ENOMEM fork failed to allocate the necessary kernel structures because memory is tight.
CONFORMING TO
The fork call conforms to SVr4, SVID, POSIX, X/OPEN, BSD 4.3.
SEE ALSO clone(2), execve(2), vfork(2), wait(2)Linux 1.2.9 1995-06-10 FORK(2)
04-01-2008
