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 #773
Difficulty: Medium
A finite-state machine (FSM) is a specialized computer developed by AT&T.
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