Lately ive been busy playing around with bash on my linux operating system, and im also using it too sort files. But this does not seem to work. Is there an alternitive way of what im doing or is it wrong?
echo -n "Are you sure you would like to delete this/these files? [y/n]"
if [ $answer == "y" ]; then
echo -n "Which File would you like to delete?"
rm $answer
else
echo "canceled!"
fi
Check the following usage of "read" command
read -n1 -p "Are you sure you would like to delete this/these files? [y/n]: " answer
if [ "$answer" == "y" ]; then
read -p "Which File would you like to delete: " filename
rm $filename
else
echo "cancelled!"
fi
Related
I'm new on bash. I want to write a script which will run iwconfig command the output should show me my wlan* mode is Managed or Monitor?
I had tried this like following but it is not working and runs the command output. I just need to echo which mode is it.
IWCONFIG_LOG="$(iwconfig)"
if [[ "$IWCONFIG_LOG" == *Mode:Managed* ]]; then
echo "Managed"
elif [[ "$IWCONFIG_LOG" == *Mode:Monitor* ]]; then
echo "Monitor Mode"
fi
Looks like you want to use Bash (not sh) in order to get this accomplish.
So, try this:
#!/bin/bash
IWCONFIG_LOG="$((iwconfig | grep Mode) 2> /dev/null)"
if [[ $IWCONFIG_LOG == *"Mode:Managed"* ]]; then
echo "Managed"
elif [[ $IWCONFIG_LOG == *"Mode:Monitor"* ]]; then
echo "Monitor Mode"
fi
Save it as a file and chmod 755 it to make it executable or execute it using "bash" instead "sh".
There are several modes, not only Managed or Monitor, so seems you only want to detect one of these two.
To see all available modes read man iwconfig
Since iwconfig writes also to standard error:
if [[ $(iwconfig 2>/dev/null | grep "Managed") ]]; then
echo "Managed"
else
echo "Monitor"
fi
or, as pointed out by #choroba in comments:
if iwconfig 2>/dev/null | grep -q Managed ; then
echo "Managed"
else
echo "Monitor"
fi
Is there a way like that you can use the "if" branch to check whether a USB-Stick is connected? And if the stick is not connected, a message should then be issued.
Something like:
if [-e /sdb1]
then
cp /home/backup/* /sdb1
rm -r /home/backup/*
echo "your files are successfully transferred."
else
echo "please be sure, if your USB-Stick is connected"
fi
No, the mount point exists whether or not a USB device is connected.
Something like this should suffice:
if [[ $(df | grep "/sdb1") && -d /sdb1 && -w /sdb1 ]]
That is if, of course, you have actually created the directory /sdb1/.
Use the findmnt utility (installed by default on RH and Ubuntu, at least)
findmnt /backup
echo $?
1
Return of 1 means not mounted.
Here is some sample code using it with an if statment
findmnt /backup >/dev/null
if [ $? = 0 ]; then
echo "It's mounted all right"
else
r=$(( RANDOM % 4 ))
echo "USB is not mounted."
case $r in
0) echo "Check the couch cushions."
;;
1) echo "I think I saw it in the kitchen."
;;
2) echo "Sign up for Prime and get free shipping!"
;;
3) echo "The dog ate it."
;;
esac
fi
while read line
do
read -p "Are you alright? (y/n) " RESP
if [ "$RESP" = "y" ]; then
echo "Here i want to do something, but prompt does not wait for the answer"
else
echo "You need more bash programming"
fi
done < find-spam-send-php-ver2.log
==> This script does not work. It does not "wait" for the yes or not option.
Please I want this script to work. Please let me know, how do modify this.
I have seen this kind of similar things in many linux installation scripts.
I have not tested this but should work,
while read line <&3
do
read -p "Are you alright? (y/n):" RESP
if [ "$RESP" = "y" ]; then
echo "Here i want to do something, but prompt does not wait for the answer"
else
echo "You need more bash programming"
fi
done 3< find-spam-send-php-ver2.log
I am creating this bashs script that has a folder path, passed as a paramter.
And if it detects that paramter is a directory, then it uses it as a path for script work.
But for some reason, it denies treating this folder path as a directory.
Which has befuddled me to no end.
This is a mounted external 3tb hard drive, works fine, no issues, what so ever.
But is mounted as /media/wdmybook/
I have this testing script to help me debug and identify the problem.
#!/bin/bash
DIR="/media/wdmybook/folder"
if grep -qs '$DIR' /proc/mounts; then
echo "It's mounted."
else
echo "It's not mounted."
fi
if [ ! -d "$DIR" ]; then
echo "Directory does not exist!"
elif [ "$DIR" != -d ]; then
echo "Not a Directory"
else
echo "Path is okay"
fi
But everytime I run it, it detects the path as an invalid directory, and it is not mounted.
So what am I missing or not seeing?
Is this a permissions issue?
I am running this on Debian Wheezy XFCE.
You should rewrite your if condition to something like that:
if [ ! -e "$DIR" ]; then
echo "Directory does not exist!"
elif [ ! -d "$DIR" ]; then
echo "Not a Directory"
else
echo "Path is okay"
fi
For details see man test
I'm new to shell scripting, my script appears to be okay, but its the flow that I'm having an issue controlling. Could someone point out what silly mistake I've made please.
#! /bin/sh
echo "Are you sure youx want to delete $1? Answer y or n"
read ans
echo $ans
if $ans = "y"|"Y"
then
mv $1 /home/parallels/dustbin
echo "File $1 has been deleted"
else echo "File $1 has not been deleted"
fi
Make your if condition like this:
if [ "$ans" = "y" -o "$ans" = "Y" ]
There are a few things wrong with your script. Some are serious, some are less so.
First, the serious problems.
As guru suggested, you need to use square brackets to surround your if condition. This is because if only tests for the output of a condition, it doesn't perform actual string comparisons. Traditionally, a program called /bin/test, which was also called /bin/[ took care of that. These days, that functionality is built in to the shell, but /bin/sh still behaves as if it's a separate program.
In fact, you can do interesting things with if when you don't use square brackets for your condition. For example, if grep -q 'RE' /path/to/file; then is quite common. The grep -q command issues no output, but simply returns a "success" or "fail" that is detected by if.
Second serious problem is that you are echoing a status that may or may not be true. I call this a serious problem because ... well, log messages simply shouldn't make false claims. If the permissions are wrong for the file in $1, or the filename contains a space, then your mv command will fail, but the message will claim that it did not. More on this later.
Next, the less serious problems.
These are mostly style and optimization things.
First off, read on most platforms includes a -p option that lets you specify a prompt. Use this, and you don't need to include an echo command.
Second, your indenting makes it hard to see what the if construct is wrapping. This isn't a huge problem in a program this small, but as you grow, you REALLY want to follow consistent standards.
Third, you can probably get more flexibility in multiple-choice questions like this if you use case statements instead of if.
After all that, here's how I'd write this script:
#!/bin/sh
if [ "$1" = "-y" ]; then
ans=y
shift
elif [ -t 0 ]; then
read -p "Are you sure you want to delete '$1' (y/N) ? " ans
fi
case "$ans" in
Y*|y*)
retval=0
if [ -z "$1" ]; then
retval=64
echo "ERROR: you didn't specify a filename." >&2
if [ ! -f "$1" ]; then
retval=66
echo "ERROR: file '$1' not found!" >&2
elif mv "$1" /home/parallels/dustbin/; then
echo "File '$1' has been deleted" >&2
else
retval=$?
echo "ERROR: file '$1' could not be deleted!" >&2
fi
;;
*)
echo "ABORT: file '$1' has not been deleted" >&2
retval=4
;;
esac
exit $retval
Aside from what's mentioned above, here are some things in this code snippet:
[ "$1" = "-y" ] - if the user specifies a -y option, then we behave as if the question was answered with a "yes".
[ -t 0 ] - this tests whether we are on an interactive terminal. If we are, then it makes sense to ask questions with read.
Y*|y*) - in a case statement, this matches any string that begins with an upper or lower case "y". Valid affirmative responses would therefore be "Y", "yes", "yellow", etc.
[ ! -f "$1" ] - this tests whether the file exists. You can man test or man sh to see the various tests available in shell. (-f may not be the most appropriate for you.)
>&2 - at the end of a line, sends its output to "standard error" instead of "standard out". This changes how output will be handled by pipes, cron, etc. Errors and log data are often sent to stderr, so that stdout can be dedicated to a program's actual output.
mv "$1" ... - The filename is in quotes. This protects you in case the filename has special characters like spaces in it.
$retval - the values for this came from a best guess of the closest item in man sysexits.
retval=$? - this is the exit status of the most recently executed command. In this case, that means we're assigning mv's exit status to the variable $retval, so that if mv failed, the whole script reports the reason for the fail, as far as mv is concerned.
You can also convert the user response to either case and just check it for respective case like
read ans
ans=${ans,,} # make 'ans' lowercase, or use ${ans^^} for making it uppercase
if [ "$ans" = "y" ]
then
....
fi
Below is the perfect code with error handling included
#!/bin/sh
echo "Are you sure you want to delete $1? Answer y or n"
read ans
echo $ans
if [ $ans == "y" ] || [ $ans == "Y" ]
then
if [ -f $1 ]
then
mv $1 /home/parallels/dustbin
echo "File $1 has been deleted"
else
echo " File $1 is not found"
fi
else
echo "File $1 has not been deleted"
fi