The shell is unix's command-line interface. You can type commands in a shell interactively, or write scripts to automate tasks.
1
vote
3answers
137 views
Shell script Variable Structure
How can I create a variable with a file name format like :
FileName pattern: SnapshotIR__somenumber.csv
I tried something like :
TODAY=$(date +"%m%d%Y")
SNAPSHOT = $(SnapshotIR$TODAY*.csv)
I ...
4
votes
3answers
136 views
Create symbolic links to files using wildcards
I want to create symlinks to multiple files:
ln -s dev-*.php 's/dev-(.*\.php)/$1/'
Results hoped for:
site.php links to dev-site.php
file.php links to dev-file.php
What's the most ...
3
votes
2answers
186 views
Get the complement of the result of an ls command
Let's say I have a directory with multiple files, all of which are either binary files (files with no declared extensions) and source files (.c extension). I do this:
$ ls
and get:
README.md ...
0
votes
3answers
108 views
Extract the base file name from a URL
url=http://www.foo.bar/file.ext; echo ${url##/*}
I expected this code to print file.ext, but it prints the whole URL. Why? How can I extract the file name?
0
votes
1answer
132 views
Send email if specified files do not exist
I am new to unix scripting. I have to do something like :
In a folder /x everyday 10Pm and next day 3 AM, 2 files are placed. I have to write a script which will check the folder /x and confirm if ...
1
vote
2answers
68 views
Cron creates vim process but does not display vim
Under MacOSX 10.8.2 I am able to run vim as follows in the bash shell:
/usr/bin/vim -c "normal G" -c 'startinsert' ~/.journal
If I put the exact same command in a script:
#! /bin/bash
export ...
1
vote
0answers
60 views
(KDE or X ) Script opens konsole in wrong virtual desktop
I have this script. I put it in ~/Desktop. I view the script on my desktop in a "Folder View" widget. When I click on the script, I get list of users, then I get an authorization dialog box ( for a ...
1
vote
1answer
130 views
How to match 2 large file and print the difference in shell script
I have 2 files.
File1 has 400k numerical records.
e.g:
1
2
3
4
5
6
.. and so on
File 2 also has 420k numerical records.
e.g:
1
2
3
4
6
.. and so on
Both these file are in unsorted manner. I want ...
2
votes
8answers
134 views
grepping dotfiles with -R correctly?
From time to time I need to find a culprit in an unknown dotfile and instead of trying to figure out which package is to be blamed (e.g. xfce4 or thunar?) and what is their naming convention (.app vs ...
2
votes
1answer
227 views
How does wc -l `ls` give the actual number of lines?
Can anyone explain to me how does this command work.
wc -l `ls`
while this command gives the total number of java lines or txt lines.
4
votes
1answer
477 views
how to compare two xml files having same data in different lines?
I have two files have same data but in different lines.
File 1:
<Identities>
<Identity>
<Id>048206031415072010Comcast.USR8JR</Id>
...
4
votes
2answers
484 views
What's a safe and portable way to split a string in shell programming?
When writing a shell script, I often want to split a string. Here's a very simple example:
for dir in $(echo $PATH | tr : " "); do
[[ -x "$dir"/"$1" ]] && echo $dir
done
This will ...
4
votes
3answers
124 views
Tar piped to split piped to scp
So I'm trying to transfer a bunch of files via SCP. Some of these are too large to be stored on the recipient (Android phone, 4GB file size limit).
The sender is almost out of space, so I can't ...
3
votes
5answers
165 views
Regex match in CLI
Is there something like a logical for the cli? I want to achieve this
mv -t newfolder *.(png|jpg)
so that alls jpg and png files are moved into newfolder. I know it could be done with
mv -t ...
3
votes
4answers
100 views
Unix - how to fetch files based on the part of a filename that is date
Say I have files say like
AA_XX_20111208
AA_XX_20111207
AA_XX_20111206
AA_XX_20111205
AA_XX_20111204
AA_XX_20111203
So using the date part,
how can i fetch previous 2 month files ?
For e.g. this ...
1
vote
2answers
56 views
How to move files from one directory to a nested directory using SSH?
I'm new to SSH. I would like to know how to move all the files, not the folder or directory, to an existing folder or directory two levels down.
2
votes
1answer
845 views
How to create bootable flash for “efi-shell”
Current Intel server chipsets include a built-in "efi-shell" which appears to basically be a simplified 'NIX with a command set suitable for manipulating some nifty UEFI boot options.
It is also the ...
3
votes
2answers
109 views
Can the shell warn me if a program is waiting for standard input?
Let's say I want to search for a string in a big file: grep foo bar.txt | less, but I actually type grep foobar.txt | less. Now, grep is waiting for me to type something on the terminal. It appears ...
1
vote
2answers
54 views
Reduce redundant logfile
I often have longer redundant log files, redundant in the sense that blocks of text repeat with minor changes. The length of the files makes it difficult to spot the actual information. I had the idea ...
1
vote
2answers
113 views
How to remove element from the list?
I have written a command that output a list of hostnames, e.g. :
clab148node11
clab148node12
clab148node15
clab148node16
Now, I would like to remove those nodes that do not respond to ping. For ...
1
vote
1answer
80 views
What does sourcing a file mean in a shell? [duplicate]
Possible Duplicate:
Different ways to execute a shell script
What happens when I issue the following command:
source devenv.csh
How does it differ from running it just as devenv.csh ?
-4
votes
2answers
121 views
Redirecting the content of a file to the command “echo”
I have a file named my_file.txt whose content is just the string Hello. How could I redirect its content to the command echo?
I know I have the commands less, cat, more... but I need to do it with ...
0
votes
2answers
109 views
What is the difference between ping -w and ping -W?
What is the -w (deadline) flag in ping for? I cannot find a description of it in the ping man page; only for -W, which takes seconds as a parameter. What is the difference between them, and how can I ...
1
vote
3answers
121 views
How to send many commands to shell and wait for the command behind ends
Hello I have around 20 commands and I have to send all of this to Unix shell, and copy the result, but I don't know how to do it.
I am not sure about what shell I have, because it is a small program ...
2
votes
1answer
329 views
Good method to compare time?
I need to check for the current time and abort the script if it is not proper time of day I am supposed to run it. Also, if anyone else runs it, it should abort.
For example: I need my script to only ...
-3
votes
1answer
134 views
Shell scripting for cron job [closed]
I have created a cronjob in Unix to execute an .sh file which will send me the output of an Excel file to my mail id once it is executed.
But now I do not want an email if there is a "NO RECORD" or ...
0
votes
2answers
101 views
Comparison of shells? [closed]
Do shells have any actual advantages or disadvantages? They can all run any binary, they all support pipes and > (output to file). Why would one choose bash over sh, or sh over ksh, etc? Why does ...
1
vote
1answer
49 views
How get program name that produced an IO error redirected to a LOG in a nohup command?
I have a program that executes other programs in the background. The main program would be programA, and the programs executed by the main one, would be program1a, program1b and program1c.
I need the ...
2
votes
3answers
300 views
Linux Shell Script - Send command over TCP to Sharp Aquos
I'm writing a shell script that needs to send an 8 character string terminated with a x0d to a Sharp Aquos TV. An example is 'POWR1 \x0d' (POWR1 followed by three spaces and LF)
The documentation ...
1
vote
1answer
121 views
Outputting last modification date to another file?
I'm trying to read the number of lines in a file, and the last modification date of that file (e.g. if it was last modified Jan 18, 2013, it should output 2013-01-18), then append the data to the ...
3
votes
1answer
60 views
Passing all files of specific filetype in current and subdirectories
I have constructed an elaborate 500+ character command with many arguments and switches to autosign multiple PDF documents.
I'm using JSignPDF and I'd like to use it's batch mode including the ...
2
votes
3answers
128 views
How to execute a bash script on multiple directories?
I have a conv.sh script that loops over MP3 files in the current directory and converts them into OGG. I have also several directories {F1, F2,..., F20} at /path/to/Files/. How should I execute ...
1
vote
3answers
55 views
Finding lists of files with specific permissions
I looked into the find command and came up with find . -maxdepth 1 -perm 521 > test.txt to output the permissions to a text file, but is it possible to do it just using, for example, simple ...
7
votes
2answers
120 views
Difference between [[ $variable ]] and [[ -n $variable ]]?
In bash, are [[ $variable ]] and [[ -n $variable ]] completely equivalent? It appears to be the case judging by the output below, but I see both forms of usage prevalent in shell scripts.
$ z="abra"
...
2
votes
3answers
158 views
What are commands to find shell keywords, built in functions and user defined functions?
I was discussing with my friend on how the commands are parsed in the shell, and he told me that bash searches the command in following order
List of aliases
List of shell keywords
List of ...
3
votes
1answer
185 views
Why does sendmail work differently in different shells?
The following code works when I directly run it in bash shell:
SUBJECT="SUBJECT-"`date`;
MAIL_FROM="abc@site.com";
MAIL_TO="abc@site.com";
MAIL_CC="abc@site.com";
MAIL_FILE="/path/of/html/body.html";
...
3
votes
4answers
98 views
mkdir -p for files
mkdir -p will create a directory; it will also make parent directories as needed.
Does a similar command exist for files, that will create a file and parent directories as needed?
2
votes
4answers
83 views
Copy Sequential Files
I have 12 files named dmp_000, dmp_001, etc, all the way to dmp_011. I would like to copy all of them to rdmp_000, rdmp_001, and so on, sequentially so the numbered files coincide. There must be an ...
2
votes
4answers
249 views
How to pipe the stdout to a file if the current command is already being piped through gzip
So I have this command I need to run then disown:
innobackupex-1.5.1 --user=root --password=**** --stream=tar ./ | gzip - > /data/myfile.tar.gz
How do I pipe any output to a file?
adding ...
7
votes
3answers
149 views
OpenSSH - map aliases in ~/.ssh/config to IP addresses in command line
Is it possible to query ~/.ssh/config in the command line? Let's say I would like to retrieve what IP address does the particular alias point to in a separate program, is it possible?
1
vote
2answers
368 views
How can I switch between different audio output hardware using the shell?
I use my laptop with an external monitor which has speakers. When the monitor is attached through HDMI I can switch (using the GUI: Sound Setting --> Hardware) between the normal laptop audio output ...
5
votes
2answers
182 views
bourne shell if [ -e $directory/file.$suffix ]
I've been looking inclusive I even checked the if manual for bash and tried in cli mode.
#!/bin/sh
CONFIG_DIR="/var/opt/SUNWldm/"
read option
if [ $option -eq 9 ]; then
ret=1
elif [ -e ...
1
vote
2answers
278 views
Parsing string by awk and get only elements without pipes or semi colons
I would like get this string line
AUGUSTYN|Stanisław|3589238
without | and :
I tried something like that:
cat baza|grep "AUGUSTYN" -n|awk -F '|' '{print $1,$2,$3,$4}'`
(baza is my file with ...
1
vote
1answer
65 views
how to setarch for each bash session
I am using bash as my default shell. I don't have root access. But I would like to customize my bash by setarch. So the question is how to do this automatically?
Currently, I have to manually run ...
3
votes
1answer
83 views
No output from inotifywait | awk
I'm attempting to use part of a one-liner found here: Script to monitor folder for new files?
When I try the following procedure I get no output whatsoever and I cannot figure out why.
In terminal ...
1
vote
1answer
43 views
Unsure about the behaviour of my script when writing to log file
I have a very simple ksh script and at certain points I want to write to a log file. I use the following commands in two places...
print "Directory listing 1:\n" > ${LogFile}
ll >> ...
3
votes
1answer
204 views
What are special prompt symbols for busybox's sh support?
I want to setup a time prompt on PS1.
But, there is no document about what are symbols the busybox support.
Is there any one know? Here are all which I knew.
PS1='\u@\h: \w \$'
2
votes
2answers
82 views
Setting a shell variable in a null coalescing fashion
I'm really fond of "null coalescing", where you can set a variable to the first "non-null" value in a list of things. Many languages support this, for example:
C#:
String myStr = string1 ?? string2 ...
2
votes
2answers
90 views
$BASHPID And $$ differ in some cases
I'm reading "BASH pocket guide of Oreilly".
It said:
The process ID of the current Bash process.
In some cases, this can differ from $$.
Above explanation , explained $BASHPID variable.
...
3
votes
3answers
120 views
Find functions, commands, and builtins [duplicate]
Possible Duplicate:
Executing user defined function in a find -exec call
Suppose I have the following bash code:
!#/bin/bash
function print_echo (){
echo "This is print_echo Function" ...
