Help For Basics Of Shell

Hi guys I just started learning Linux, Need some help writing the script for the following

1. An argument of the form-6 sets the script to display the first 6 lines of the succeeding file(s). the default should be 5.

2. Anything else of the form "-x" should produce an error message

3. For a file name, display the first _lines of the file

hi,

I am newbie in Linux shell scripting.Can anybody help me to check the presence of file identified by variable in Shell scripting?

For example: I am reading the content of a file using while command as below:
"while read -r line
do
code block
done < file_name"

Now in this case every line in file gets stored in the variable 'line' one by one.Problem here is every line in the file is nothing but the file_path of another file say xyz.txt and I am checking presence of this xyz.txt file using below command:
if [-f $line]
as 'line' is the variable which stores file path of xyz.txt but it is not working. It is unable to check the presence of this xyz.txt file as i am addressing it with the variable 'line'.

Please help me.Thanks in advance.

hello,

i am trying to make a table from some files. i used this to record how much "RD_" field i have in my file. Quote:
grep -o 'RD_' $f|grep -c 'RD_'
forexample i got 5 "RD_" fields now i want to print 5 number of fields from another file starting from 2nd field. i did it mannully like Quote:
awk 'NR==1{print"{"$2","$3","$4","$5","$6","0.0000",""0.0000""}"","}' $file
i want to make it work together and a bit auto matic like PHP Code:
awk 'NR==1{print"{"$2"to "$5"," apend zeros to make it total 7 fields"}"","}' $file 


your coments would be apreciated
thanks alot

Hi All,

Im trying to create a script which checks the creation time of a file and if it is more than ten minutes, send out an alert.

For ex : Creation date of file is 10:30 AM
current time is 10:45 AM

Then send an alert/ message.

This is the script i wrote below :

Code:

#!/bin/ksh

filename="/apps/log/file.txt"

if [ -f "${filename}" ]
then
        createTime=`ls -lad "${filename}" | awk '{print $8}'`
        echo "$createTime"
        currentTime=`date '+%M'`
        echo "$currentTime"
        DIFF=$(( $currentTime - $createTime )) 
        echo "$DIFF"

else

        exit 1

fi

I am getting syntax error on the subraction when i try to run this script . I can understand that creation time and current time is in different format thats y this error throws, but i dont know how to rectify it .

I need to find out if the file creation time is more than ten minutes.

Please help me in achieving this output.

hello all,

please help me with python ftplib. i was trying to copy files from my linux machine to a windows server using ftplib. everything was working good. but i'm only able to copy files from the same directory the script is. how do i copy files from a different directory? i always get "file not found error message". here's my code :

Code:

tester_name = str (socket.gethostname())
def upload(ftp, file):
    ext = os.path.splitext(file)[1]
    if ext in (".txt", ".htm", ".html"):
        ftp.storlines("STOR " + file, open(file))
    else:
        ftp.storbinary("STOR " + file, open(file, "rb"), 1024)



parse_source_path = ('/path/to/where/i/go/')
parse_source_file_list = os.listdir(parse_source_path)

ftp = ftplib.FTP("server_IP")
ftp.login("username", "pass")

folder_list = []

ftp.dir(folder_list.append)

if str(tester_name) not in str(folder_list) :
    ftp.mkd("%s"%tester_name)
    ftp.cwd("%s"%tester_name)
    for files in parse_source_file_list :
        print files
        upload(ftp, files)


else :
    print "later"

Hello,

I am working on a board (sbc6000x with at91sam9261 micro, linux 2.6.24 to be precise) and having some fun making script i wanted to make real application.
The board is coming with a cross compilation toolchain. When trying to make a simple "hello world" executable to print on the terminal there is no problem.
I open my terminal, give the path of the compiler, cd into the folder where my .c file is and then i type :
Code:

arm-linux-gcc -o hello hello.c

Which create my executable "hello" and this one is working. But like i said, this program only played with the terminal.

The board is starting with a script calling another executable which use the lcd display, i have the source of this executable. My idea was to look at what was in the source of this application (lots of folders and files) in order to understand how it was working. I wanted to test the toolchain on the source (with the makefile) to see if i was able to generate an executable from a application with folderS/fileS but when i try to "make" it i have this error.

In my understanding this is an object file but aside from that i don't see why it would not works.

Thank you for your future answers !

I have simple c code and I want to make .bin file to run on friendly arm board. In redhat I install cross compile gcc and Use "gcc -o hello hello.c" this command to make object file. when I run this file in friendly arm it give "line 1: syntax error: unexpected "(" "

Thanks
--
Abdul Wahab

I'm running LinuxLite 2.0 32bit on a Dell 3000.

I have never come across anything like this and to tell you, I am stumped.

Here are the contents of my crontab file:

Code:

# Edit this file to introduce tasks to be run by cron.
#
# Each task to run has to be defined through a single line
# indicating with different fields when the task will be run
# and what command to run for the task
#
# To define the time you can provide concrete values for
# minute (m), hour (h), day of month (dom), month (mon),
# and day of week (dow) or use '*' in these fields (for 'any').#
# Notice that tasks will be started based on the cron's system
# daemon's notion of time and timezones.
#
# Output of the crontab jobs (including errors) is sent through
# email to the user the crontab file belongs to (unless redirected).
#
# For example, you can run a backup of all your user accounts
# at 5 a.m every week with:
# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
#
# For more information see the manual pages of crontab(5) and cron(8)
#
# m h  dom mon dow   command
*/10 * * * * /usr/bin/arecord -t wav -f cd -d 42 /home/randy/Music/lanting$(date "+\%^b\%d\%y").wav

If I run this from the terminal, everything is fine. It properly records the audio:

Code:

/usr/bin/arecord -t wav -f cd -d 42 /home/randy/Music/lanting$(date "+\%^b\%d\%y").wav

If I run this as it is shown in my crontab file, it records but there is no audio recorded.:


Code:

*/10 * * * * /usr/bin/arecord -t wav -f cd -d 42 /home/randy/Music/lanting$(date "+\%^b\%d\%y").wav

What could be causing this? I tried different cron settings for example 15 14 * * 2

This recorded at 2:15pm on Tuesday (today) but no audio. Yet if I run the code as mentioned above, from the terminal without the cron settings, the recording is fine.

Any ideas what I should do?

Hello am a newbie to linux,
I tried to install cygwin for windows,all i need is i need to write a shell program for a batch file i already have, I am not able to do this.
My batch file content looks like

SET JAVA_HOME=..\jdk
SET CLASSPATH="%CLASSPATH%;../lib/A.jar;../lib/slf4j-api-1.6.1.jar;../lib/slf4j-simple-1.6.1.jar"

%JAVA_HOME%\bin\java.exe com.A ../conf/C.properties

PAUSE

this works perfectly, I try to write a shell program which is failing when i check it through cygwin. i am not able to set the export to java_home.
The pblm i face is say my current directory where my shell program is 'Z'
then i want to get back to 'y' where X has two sub folders y and z

X
-Y (is jdk )
-Z (where shell pgm resides)

cd ../ or any combination of cd doesnot work in my shell script.

Please help me. Any help is greatly appreciated

I am facing problem in enabling the DNS Log making in named.conf file.
My /etc/named.conf file structure is as follows:
-------------------------------------------------------------
//
// named.conf
//
// Provided by Red Hat bind package to configure the ISC BIND named(8) DNS
// server as a caching only nameserver (as a localhost DNS resolver only).
//
// See /usr/share/doc/bind*/sample/ for example named configuration files.
//

options {
listen-on port 53 { 127.0.0.1; 10.40.124.2; };
listen-on-v6 port 53 { ::1; };
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
allow-query { localhost; 10.40.124.2; };
recursion yes;

dnssec-enable yes;
dnssec-validation yes;
dnssec-lookaside auto;

/* Path to ISC DLV key */
bindkeys-file "/etc/named.iscdlv.key";

managed-keys-directory "/var/named/dynamic";
};

logging {
channel default_debug {
file "/var/log/named.run";
severity dynamic;
print-time yes;
};

channel queries_channel {
file "/var/log/queries.log";
severity dynamic;
print-time yes;
print-severity yes;
};
channel security_channel {
file "/var/log/security.log" versions 3 size 5m;
severity debug 3;
print-category yes;
print-severity yes;
print-time yes;
};

channel update_security_channel {
file "/var/log/updates.log" versions 3 size 5m;
severity debug 3;
print-category yes;
print-severity yes;
print-time yes;
};

channel dnssec_channel {
file "/var/log/dnssec.log" versions 3 size 5m;
severity debug 3;
print-category yes;
print-severity yes;
print-time yes;
};

channel xfers_channel {
file "/var/log/zone_transfers.log" versions 3 size 5m;
severity debug 3;
print-category yes;
print-severity yes;
print-time yes;
};

category queries { queries_channel; };
category security { security_channel; };
category update-security { update_security_channel; };
category dnssec { dnssec_channel; };
category xfer-out { xfers_channel; };
};
zone "." IN {
type hint;
file "named.ca";
};

include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";
----------------------------------------------------------------
My DNS Server works fine. Only it cannot make the log.
when I will run this command:
#dig -x 10.40.124.2
the result comes fine but the log is not make in /var/log/queries.log file.
The named is running without chroot enviroment.
Please help me in solving this.