11-25-2009
Thanks jim
echo ${PIPESTATUS[0]}
shows the exit code of the first command
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
can you redirect STDIN with command arguments?
I have tried this approach:
# ./script -option <argument1> <argument2> 0<$2
# $2: ambiguous redirect
Is this possible? (4 Replies)
Discussion started by: prkfriryce
4 Replies
2. Programming
Hi,
Program A: uses pipe()
I am able to read the stdout of PROGAM B (stdout got through system() command) into PROGRAM A using:
* child
-> dup2(fd, STDOUT_FILENO);
-> execl("/path/PROGRAM B", "PROGRAM B", NULL);
* parent
-> char line;
-> read(fd, line, 100);
Question:... (2 Replies)
Discussion started by: vvaidyan
2 Replies
3. Programming
Hi all
I've run into a snag in a program of mine where part of what I entered in at the start of run-time, instead of the current value within printf() is being printed out.
After failing with fflush() and setbuf(), I tried the following approach
void BufferFlusher()
{
int in=0;... (9 Replies)
Discussion started by: JamesGoh
9 Replies
4. Shell Programming and Scripting
#!/bin/sh
exec 0</dev/null
exec 1>/dev/null
ls -l /proc/self/fd >&2 produces total 0
lr-x------ 1 tyler users 64 Feb 18 10:38 0 -> /proc/7886/fd
lrwx------ 1 tyler users 64 Feb 18 10:38 1 -> /dev/pts/4
lrwx------ 1 tyler users 64 Feb 18 10:38 2 -> /dev/pts/4 I've verified the shell is... (10 Replies)
Discussion started by: Corona688
10 Replies
5. Shell Programming and Scripting
Hi,
I am working on a project where I have to generate and execute nasm code on-the-fly. I generate the code in a file program.asm and then execute it.This output is to stdout which i redirect to an output file which i read back to compare results:
system("nasm -f elf program.asm >... (5 Replies)
Discussion started by: doc_cypher
5 Replies
6. Programming
All,
Ok...so I know I *should* be able to control a process's stdin and stdout from the parent by creating pipes and then dup'ing them in the child. And, this works with all "normal" programs that I've tried. Unfortunately, I want to intercept the stdin/out of the scp application and it seems... (9 Replies)
Discussion started by: DreamWarrior
9 Replies
7. Programming
Hi,
i am using the below program to read from the standard input or to write to standard out put.
i know that using highlevel functions this can be done better than what i have done here.
i just want to know is there any other method by which i find the exact number of characters ( this... (3 Replies)
Discussion started by: MrUser
3 Replies
8. UNIX for Dummies Questions & Answers
Hallo,
i have a script like:
if ;then
echo "OK"
else
echo "ERROR $2 is missing"
fi;
if ;then
touch $2
fi;
if ;then
cat $1 | grep xy > $2 (1 Reply)
Discussion started by: eightball
1 Replies
9. UNIX for Advanced & Expert Users
I want to differentiate the STDOUT and STDERR messages in my terminal .
If a script or command is printing a message in terminal I want to differentiate by colors,
Is it possible ?
Example:
$date
Wed Jul 27 12:36:50 IST 2011
$datee
bash: datee: command not found
$alias ls
alias... (2 Replies)
Discussion started by: ungalnanban
2 Replies
10. Shell Programming and Scripting
Well.. let's say i need to write a pretty simple script.
In my script i have 2 variables which can have value of 0 or 1.
$VERBOSE
$LOG
I need to implement these cases:
($VERBOSE = 0 && $LOG = 0) => ONLY ERROR output (STDERR to console && STDOUT to /dev/null)
($VERBOSE = 1... (5 Replies)
Discussion started by: Marmz
5 Replies
LEARN ABOUT FREEBSD
stdin
FD(4) BSD Kernel Interfaces Manual FD(4)
NAME
fd, stdin, stdout, stderr -- file descriptor files
DESCRIPTION
The files /dev/fd/0 through /dev/fd/# refer to file descriptors which can be accessed through the file system. If the file descriptor is
open and the mode the file is being opened with is a subset of the mode of the existing descriptor, the call:
fd = open("/dev/fd/0", mode);
and the call:
fd = fcntl(0, F_DUPFD, 0);
are equivalent.
Opening the files /dev/stdin, /dev/stdout and /dev/stderr is equivalent to the following calls:
fd = fcntl(STDIN_FILENO, F_DUPFD, 0);
fd = fcntl(STDOUT_FILENO, F_DUPFD, 0);
fd = fcntl(STDERR_FILENO, F_DUPFD, 0);
Flags to the open(2) call other than O_RDONLY, O_WRONLY and O_RDWR are ignored.
IMPLEMENTATION NOTES
By default, /dev/fd is provided by devfs(5), which provides nodes for the first three file descriptors. Some sites may require nodes for
additional file descriptors; these can be made available by mounting fdescfs(5) on /dev/fd.
FILES
/dev/fd/#
/dev/stdin
/dev/stdout
/dev/stderr
SEE ALSO
tty(4), devfs(5), fdescfs(5)
BSD
June 9, 1993 BSD