Visit Our UNIX and Linux User Community


Redirecting


 
Thread Tools Search this Thread
Top Forums Programming Redirecting
# 1  
Old 08-16-2005
Redirecting

How to redirect the contents of a file to a command?

The contents of the file are the arguments necessary for the command.

thx in advance.

bye
svh
# 2  
Old 08-16-2005
This may be kind of cheating, but:
Code:
include <stdlib.h>

int main(int argc, char *argv[])
{
  return(system("./some-program `cat filename`"));
}

Or if you must do it from C alone, look into the execvp family of functions.
# 3  
Old 08-17-2005
Redirecting

I will try it out

thx,
bye
# 4  
Old 08-17-2005
well, above c program will do absolutely nothing.
if your shell script code is
Code:
./prog < file

then you can try this:

Code:
#include <stdio.h>

int main()
{
    int c;

    while( (c = fgetc(stdin)) != EOF )
    {
        /* do something with input char */
    }
}

# 5  
Old 08-18-2005
Quote:
Originally Posted by fdarkangel
well, above c program will do absolutely nothing.
Considering I actually wrote it and tested it before posting here, I think that pronouncement is premature. I'm presuming he means arguments when he says arguments, not stdin.
# 6  
Old 08-22-2005
Or you can use Shell's "Here Documents" if you wanna put your command in the same place as your data on which that command will act.

$cat findpattern.sh
grep 'pattern' <<End # Here document tag
Hi here is pattern
Pattern here, but escape from grep
No grep in this line
Can't find here
Pattern here again
pattern here
End # Here document tag

$./findpattern.sh
Hi here is pattern
pattern here

Previous Thread | Next Thread
Test Your Knowledge in Computers #674
Difficulty: Medium
Wi-Fi does not use any parts of the IEEE 803 protocol.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Redirecting the output

For example, if we run the below command, symcfg list -thin -pool , results in an output most of the times and if the out is generated i'm able to redirect the output to a file. but sometimes it doesnt result any output and even though the output is being redirected, i can see "No Thin Pools "... (2 Replies)
Discussion started by: web2moha
2 Replies

2. Shell Programming and Scripting

redirecting help

I am trying to create the file and redirect the output in the same command line which is line 4 in the below program. #!/bin/bash read -p "Enter File Name:" value1 echo "Your File Name is $value1" sed 's/abcd/'$value1'/g' abcd_calls > $value1_calls This is the error it generates ... (3 Replies)
Discussion started by: learnbash
3 Replies

3. Linux

Telnet redirecting

Hey guys, i want to be able to get rid of the following output that telnet spits out to the terminal. i have a script that runs telnet to about 5 hosts and checks to make sure connectivity works. Connection closed by foreign host. Connection closed by foreign host. Connection closed by... (2 Replies)
Discussion started by: SkySmart
2 Replies

4. Shell Programming and Scripting

Redirecting stdin from fd 3-9?

Hi I'm trying to do something on the bash command line that I will later put into a bash shell script. I'm trying to take a program that reads stdin (using getline) and be able to keep it running in the background and fire "commands" to it. So what I thought I should do was to try taking... (3 Replies)
Discussion started by: niceguyeddie
3 Replies

5. Shell Programming and Scripting

redirecting symbols

Can anyone please tell me what the following do 1. < 2. << Thanks Calypso (1 Reply)
Discussion started by: Calypso
1 Replies

6. Web Development

Apache redirecting

Dear All I need to redirect requests coming in on a second domain, to a page within an existing web site. So basicly http:\\webtest should be redirected to http:\\ustnd5\ukt\newsroom\newsroom.jsp I have the line ProxyPassReverse /ukt/newsroom/newsroom.jsp http://webtest:10080/ ... (1 Reply)
Discussion started by: wjones
1 Replies

7. Shell Programming and Scripting

Redirecting to stdin

Hi, I'm having trouble with my script. I have to select different choices without any interaction from a menu that looks like : a - xxxxxxxxxxxxxx b - xxxxxxxxxxxxxx c - xxxxxxxxxxxxxx d - xxxxxxxxxxxxxx I tried things like : echo "a" >&0 read < echo "a" but none worked. Any... (4 Replies)
Discussion started by: flame_eagle
4 Replies

8. UNIX for Advanced & Expert Users

MX redirecting

I in no means consider myself a expert in unix however my question is a little more complex. I am running a mac os 10 server and all web settings and email settings have been set up using the unix terminal. I am in the process or redirecting my mxrecords to a spam filtering company but i am... (11 Replies)
Discussion started by: nbredthauer
11 Replies

9. Shell Programming and Scripting

Redirecting OUTPUT

Hi, I want to move the output of a command/script to a file as well as to to be displayed on stdout. Can anybody help me in this. Thanks in advace .. -Chanakya M (1 Reply)
Discussion started by: Chanakya.m
1 Replies

10. Shell Programming and Scripting

using redirecting from awk

Well this is what im doing, im writing a script that you pass 3 variables into. Filename, delimiter or "FS in AWK", and a string of columbs you want to keep 1,2,4,5... Just modifing a data file and rewriting with a different extension. My problem atm is using awk to seperate the "columb String"... (2 Replies)
Discussion started by: ugh
2 Replies

Featured Tech Videos