10-17-2010
See man popen. You can read the output from a program without the temporary file in between.
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
"Is there any substituation of last command or script syntax which can be used as a user. As far I know the "last" command is being used to display information about previous logins. A member of adm group or the user adm can execute it only.
Thanks in advance for your usual help.
Ghazi (6 Replies)
Discussion started by: ghazi
6 Replies
2. UNIX for Dummies Questions & Answers
Hi,
i want to write a script that executes a program (exec?) .
this program then requires a filename as input.
how do i give it this input in the script so the program will be complete run and close by the script.
e.g.
exec prog.exe
program then asks for filename
"enter filename:"... (1 Reply)
Discussion started by: tuathan
1 Replies
3. Shell Programming and Scripting
Hi,
What is the actual difference between these two? Why the following code works for process substitution and fails for command substitution?
while IFS= read -r line; do echo $line; done < <(cat file)executes successfully and display the contents of the file
But,
while IFS='\n' read -r... (3 Replies)
Discussion started by: royalibrahim
3 Replies
4. Shell Programming and Scripting
Hey, I was trying to figure out how to launch a program from the command line, and it works if you pass it a config file. I was thinking about writing a script to dynamically create the config file and pass it to the command using something like command substitution (so I don't actually have to... (3 Replies)
Discussion started by: bj0
3 Replies
5. UNIX for Dummies Questions & Answers
I know this script is crummy, but I was just messing around.. how do I get sed's insert command to allow variable expansion to show the filename?
#!/bin/bash
filename=`echo $0`
/usr/bin/sed '/#include/ {
i\
the filename is `$filename`
}' $1
exit 0 (8 Replies)
Discussion started by: glev2005
8 Replies
6. UNIX for Dummies Questions & Answers
Hey, guys!
Trying to research this is such a pain since the read command itself is a common word. Try searching "unix OR linux read command examples" or using the command substitution keyword. :eek:
So, I wanted to use a command statement similar to the following.
This is kinda taken... (2 Replies)
Discussion started by: ProGrammar
2 Replies
7. Shell Programming and Scripting
Hi,
I almost always use back quotes in scripts to assigin output of a command to a variable.
eg: file=`basename a/b/c/d/file`
year_mon=`date +%Y%m`
But the same can be achieved like:
file=$(basename a/b/c/d/file)
year_mon=$(date +%Y%m)
I would like to know if there is... (3 Replies)
Discussion started by: wanderingmind16
3 Replies
8. Shell Programming and Scripting
I have the following code:
strfuture=abcdefghi
ver=${strfuture:${count}:1}
mj7777_ver=${ver} start_mj7777_iteration
let count=count+1
When it is executed I get bad substitution. The same if I use
ver=${strfuture:$count:1}
mj7777_ver=${ver}... (6 Replies)
Discussion started by: Bruble
6 Replies
9. Shell Programming and Scripting
Oracle Linux 5.6, 64-bit
Given the following snippet
wrkvar=`sqlplus -s / as sysdba <<EOF
set echo off feedback off head off trimsp on
select count(*) from v\$parameter
where name in ('db_file_name_convert','log_file_name_convert')
and value is not null;
EOF`
echo wrkvar=$wrkvarProduces... (2 Replies)
Discussion started by: edstevens
2 Replies
10. Shell Programming and Scripting
Hi folks,
I totally dislike asking questions in forums but this one eats up to much of my time I need to spend on other topics.
I have a shell-script in which I call a terminal.
I want to invoke bash inside the terminal and print a message inside bash with aid of a here document.
See... (7 Replies)
Discussion started by: bluntroller
7 Replies
LEARN ABOUT ULTRIX
pclose
popen(3) Library Functions Manual popen(3)
Name
popen, pclose - initiate I/O to/from a process
Syntax
#include <stdio.h>
FILE *popen(command, type)
char *command, *type;
pclose(stream)
FILE *stream;
Description
The arguments to are pointers to null-terminated strings containing respectively a shell command line and an I/O mode, either "r" for read-
ing 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 should be closed by 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.
Diagnostics
The routine returns a null pointer if files or processes cannot be created, or the shell cannot be accessed.
The routine returns -1 if stream is not associated with a `popened' command.
Restrictions
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 For further information, see
The routine always calls and never calls
See Also
sh(1), pipe(2), wait(2), system(3), fclose(3s), fopen(3s)
popen(3)