Try this:
usage:
Is that what you meant? This works in "standard" bash - I don't have mks so I don't know if bash under mks is complete implementation.
Hi I am having trouble with a script to export individual schemas to tape from an oracle database. Basicaly I need to export each shema through a pipe with compression and store each shema name in a file with the relevant tape marker. (4 Replies)
Hi...Can anyone please guide me on FIFO Pipes in UNIX.I have lerant things like creating fifo pipes,using them for reads and writes etc.I want to know what is the maximum amount of memory that such a pipe may have? Also can anyone guide me on where to get info on this topic from? (1 Reply)
The following code does not work (zsh, Solaris), but works without the first line (files instead of pipes) :confused:
mkfifo p1 p2
echo "Hello" | tee p1 > p2 &
paste p1 p2
I would high appreciate any help to fix it. (9 Replies)
Hi,
Please help me on this.
I am creating a named pipe in a kshell script.
I am using mkfifo pipe_name command to create the pipe.
I want to remove the named pipe after my work is completed.
How can i do that. (8 Replies)
hi,
i am working on a script for oracle export, m using a parameter file...
i want to compress the dump file that is generated..
in my script following is the code i have written.
i am not able to generata .gz file
mknod /tmp/exp_tesd1_pipe p
gzip -cNf... (4 Replies)
Tried the following on Hpux 11.11, using both ksh, and dtksh
$diff <(sort file1) <(sort file2)
$ ksh: syntax error: `(' unexpected
Strange thing is I tried the same command under RHEL5 using ksh 93 and it works fine. Does anyone know if this is possible on HPUX without the use of... (0 Replies)
Hi All,
I want to use the find command with MKS Toolkit. I am using the below syntax,
find.exe . "pattern" -print > tmp.txt
This command is working fine in Unix, but not in MKSToolkit. But it is exiting with 1. Can any one help me how to use the find command with MKS Toolkit.
Thanks for your... (7 Replies)
Dear community,
I communicate with an external program (maxima) using named pipes. If I use a text file to capture the output (maxima > out.txt) i can see the programs answer directly after the input written into the file. But if bypass the output into a named pipe (maxima > pipe) and capture it... (1 Reply)
Discussion started by: Pustekuchen
1 Replies
LEARN ABOUT MOJAVE
pclose
POPEN(3) BSD Library Functions Manual POPEN(3)NAME
pclose, popen -- process I/O
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdio.h>
FILE *
popen(const char *command, const char *mode);
int
pclose(FILE *stream);
DESCRIPTION
The popen() function ``opens'' a process by creating a bidirectional pipe, forking, and invoking the shell. Any streams opened by previous
popen() calls in the parent process are closed in the new child process. Historically, popen() was implemented with a unidirectional pipe;
hence, many implementations of popen() only allow the mode argument to specify reading or writing, not both. Because popen() is now imple-
mented using a bidirectional pipe, the mode argument may request a bidirectional data flow. The mode argument is a pointer to a null-termi-
nated string which must be 'r' for reading, 'w' for writing, or 'r+' for reading and writing.
The command argument is a pointer to a null-terminated string containing a shell command line. This command is passed to /bin/sh, using the
-c flag; interpretation, if any, is performed by the shell.
The return value from popen() is a normal standard I/O stream in all respects, save that it must be closed with pclose() rather than
fclose(). Writing to such a stream writes to the standard input of the command; the command's standard output is the same as that of the
process that called popen(), unless this is altered by the command itself. Conversely, reading from a ``popened'' stream reads the command's
standard output, and the command's standard input is the same as that of the process that called popen().
Note that output popen() streams are fully buffered, by default.
The pclose() function waits for the associated process to terminate; it returns the exit status of the command, as returned by wait4(2).
RETURN VALUES
The popen() function returns NULL if the fork(2) or pipe(2) calls fail, or if it cannot allocate memory.
The pclose() function returns -1 if stream is not associated with a ``popened'' command, if stream already ``pclosed'', or if wait4(2)
returns an error.
ERRORS
The popen() function does not reliably set errno.
SEE ALSO sh(1), fork(2), pipe(2), wait4(2), fclose(3), fflush(3), fopen(3), stdio(3), system(3)BUGS
Since the standard input of a command opened for reading shares its seek offset with the process that called popen(), if the original process
has done a buffered read, the command's input position may not be as expected. Similarly, the output from a command opened for writing may
become intermingled with that of the original process. The latter can be avoided by calling fflush(3) before popen().
Failure to execute the shell is indistinguishable from the shell's failure to execute command, or an immediate exit of the command. The only
hint is an exit status of 127.
The popen() function always calls sh(1), never calls csh(1).
HISTORY
A popen() and a pclose() function appeared in Version 7 AT&T UNIX.
Bidirectional functionality was added in FreeBSD 2.2.6.
BSD May 3, 1995 BSD