01-13-2014
Hello Don, thanks so much for your reply. I'm using Advanced Programming in the Unix Environment and Modern Operating Systems as my reference.
As for the question, I just want the parent to get the command execution result(successful or not) from the child, because I want to do &&(conditional execution). If execvp successfully executes in the child, how does the parent know it because it does not return any value. Thanks.
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hello all,
Can someone explain to me the advantage between using subshell over a function call in scripts? To me these are the same. Am I wrong to think this? (4 Replies)
Discussion started by: larry
4 Replies
2. Shell Programming and Scripting
Hi,
If this is the array that is being returned to me:
How would I get the values for each of the 3 records?
This works for 1 Record:
foreach $item (@results)
{
($id, $id2, $name, $date, $email) = split(/\|/, $item, 5);
print "$name<br>";
} (2 Replies)
Discussion started by: novera
2 Replies
3. UNIX for Advanced & Expert Users
I am going to take up a position in Data & Network Security.
I would need to write network shell scripts doing the following task:
Going to around 2000 servers and findout which groups has access to each servers and which ids are there in each group that has access.
I need to implement... (1 Reply)
Discussion started by: pinnacle
1 Replies
4. Shell Programming and Scripting
Hello to all,
I am looking for a way to display only the names of function (calls & definition) of a C++ source code.There is already a post related to this, but the script is to find the functions using a specific variable, and the replies are not that convincing since they cannot be used for... (2 Replies)
Discussion started by: frozensmilz
2 Replies
5. Shell Programming and Scripting
Hi, I hope the title does not scare people to look into this thread but it describes roughly what I'm trying to do. I need a solution in PHP.
I'm a programming beginner, so it might be that the approach to solve this, might be easier to solve with an other approach of someone else, so if you... (0 Replies)
Discussion started by: lowmaster
0 Replies
6. Shell Programming and Scripting
Hello All
I have a xml file with many sets of records
like this
<mytag>mydata</mytag>
<tag2>data&</tag2>
also same file can be like this
<mytag>mydata</mytag>
<tag2>data&</tag2>
<tag3>data2&data3</tag3>
Now i can grep & and replace with & for whole file but it will replace all... (4 Replies)
Discussion started by: lokaish23
4 Replies
7. Shell Programming and Scripting
Hi, I have text file abc.txt. In this file, I have the following data.
Input:
Mr Smith & Mrs Smith
Mr Smith &apos Mrs Smith
Mr Smith & Mrs Smith
Mr Smith& Mrs Smith
Mr Smith &Mrs Smith
Output:
Mr Smith & Mrs Smith
Mr Smith &apos Mrs Smith
Mr Smith & Mrs Smith
Mr Smith&... (4 Replies)
Discussion started by: naveed
4 Replies
8. UNIX for Dummies Questions & Answers
How to use MAN to find information about read() and write() function ?
The command "man read" show some rubbish, for example "man open" show great information about function I need. (2 Replies)
Discussion started by: bbqtoss
2 Replies
9. Shell Programming and Scripting
Hi All,
Do you have any sample script,
- auto get file from SFTP remote server and delete file in remove server after downloaded.
- only download specify filename
- auto upload file from local to SFTP remote server and delete local folder file after uploaded
- only upload specify filename
... (3 Replies)
Discussion started by: weesiong
3 Replies
10. Homework & Coursework Questions
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:
2. Relevant commands, code, scripts, algorithms:
#! /bin/ksh
v="ORG_ID"
... (2 Replies)
Discussion started by: sujitdas2104
2 Replies
FORK(2) System Calls Manual FORK(2)
NAME
fork - create a new process
SYNOPSIS
pid = fork()
int pid;
DESCRIPTION
Fork causes creation of a new process. The new process (child process) is an exact copy of the calling process except for the following:
The child process has a unique process ID.
The child process has a different parent process ID (i.e., the process ID of the parent process).
The child process has its own copy of the parent's descriptors. These descriptors reference the same underlying objects, so that, for
instance, file pointers in file objects are shared between the child and the parent, so that an lseek(2) on a descriptor in the child
process can affect a subsequent read or write by the parent. This descriptor copying is also used by the shell to establish standard
input and output for newly created processes as well as to set up pipes.
The child processes resource utilizations are set to 0; see setrlimit(2).
RETURN VALUE
Upon successful completion, fork returns a value of 0 to the child process and returns the process ID of the child process to the parent
process. Otherwise, a value of -1 is returned to the parent process, no child process is created, and the global variable errno is set to
indicate the error.
ERRORS
Fork will fail and no child process will be created if one or more of the following are true:
[EAGAIN] The system-imposed limit on the total number of processes under execution would be exceeded. This limit is configuration-
dependent.
[EAGAIN] The system-imposed limit MAXUPRC (<sys/param.h>) on the total number of processes under execution by a single user would be
exceeded.
[ENOMEM] There is insufficient swap space for the new process.
SEE ALSO
execve(2), wait(2)
3rd Berkeley Distribution May 22, 1986 FORK(2)