The "more" command can take input from either a pipe or from the command line.
The "tr" command is one command which only takes input from standard input.
The glob is expanded before the rm is executed. Therefore the "rm" attempts to remove the file "abc" twice.
Hi!
Im new to all this but the computer club im in has unix i think.
now my questions.
1.is it NTFS i need to partion the harddrive with to be able to use unix?
2.Unix and Linux whats the diffrense?yes im a noob got no idea been using crap windows for ages and hate it.
3.I got a win98... (2 Replies)
Hello Everbody
I hope you can give me a hand, I have some questions
The first one itīs about some message that I donīt know what means, I was looking about it. but nothing. This is the message
rsh: connection from bad port
bsd-gw: Error reading from connection: Bad file number
And my... (4 Replies)
Hi everyone im new to this forums, i just wanted to get started by asking a few question(Im a Unix newbie)
1. How do i sort a file called "dirr" in a ascending order on the 3rd column
2. what does alias on=who do
Thanks in advance!!! (1 Reply)
hey all, I have question when am writing simple shell...
in the child am calling execvp, i want the parent to know when execvp returns - 1. how can i let the parent know the result of execvp
thanks in advance (9 Replies)
1.) I am to write scripts that will be phasetest folder in the home directory.
2.) The folder should have a set-up,phase and display files
I have written a small script which i used to check for the existing users and their password.
What I need help with:
I have a set of questions in a... (19 Replies)
Hello,
I would like to know how we can highlight/select a section of a file in vi and delete that section if we don't want to use the dd command to delete one line at at time. There is one where we don't want to delete the whole line , but up to a certain word. (2 Replies)
Discussion started by: Pouchie1
2 Replies
LEARN ABOUT BSD
pclose
POPEN(3) Library Functions Manual POPEN(3)NAME
popen, pclose - initiate I/O to/from a process
SYNOPSIS
#include <stdio.h>
FILE *popen(command, type)
char *command, *type;
pclose(stream)
FILE *stream;
DESCRIPTION
The arguments to popen are pointers to null-terminated strings containing respectively a shell command line and an I/O mode, either "r" for
reading or "w" for writing. It creates a pipe between the calling process and the command to be executed. The value returned is a stream
pointer that can be used (as appropriate) to write to the standard input of the command or read from its standard output.
A stream opened by popen should be closed by pclose, which waits for the associated process to terminate and returns the exit status of the
command.
Because open files are shared, a type "r" command may be used as an input filter, and a type "w" as an output filter.
SEE ALSO pipe(2), fopen(3S), fclose(3S), system(3), wait(2), sh(1)DIAGNOSTICS
Popen returns a null pointer if files or processes cannot be created, or the shell cannot be accessed.
Pclose returns -1 if stream is not associated with a `popened' command.
BUGS
Buffered reading before opening an input filter may leave the standard input of that filter mispositioned. Similar problems with an output
filter may be forestalled by careful buffer flushing, for instance, with fflush, see fclose(3S).
Popen always calls sh, never calls csh.
7th Edition May 15, 1985 POPEN(3)