Exporting environment variable in bash script - it doesnt work - bash

I wrote a little bash script to export environment variable:
#!/bin/bash
echo "Pass a path:"
read path
echo $path
defaultPath = /home/katie/Desktop
if [ -n "$path" ]; then
echo "Path is empty! Exporting default path ..."
export my_var=$defaultPath
else
export my_var=$path
fi
but I got error:
defaultPath: command not found
How to fix it?
WORKNG VERSION:
#!/bin/bash
echo "Pass a path:"
read path
echo $path
defaultPath=/home/user/Desktop
if [ -n "$path" ]; then
export my_var=$path
else
echo "Path is empty! Exporting default path ..."
export my_var=$defaultPath
fi

No whitespace is allowed surrounding the = in a variable assignment:
defaultPath=/home/katie/Desktop
With spaces, the line is interpreted as a simple command that attempts to execute the command defaultPath with two arguments, = and /home/katie/Desktop.

Related

How do I reference the current directory inside a terminal command file? [duplicate]

How can I determine the name of the Bash script file inside the script itself?
Like if my script is in file runme.sh, then how would I make it to display "You are running runme.sh" message without hardcoding that?
me=`basename "$0"`
For reading through a symlink1, which is usually not what you want (you usually don't want to confuse the user this way), try:
me="$(basename "$(test -L "$0" && readlink "$0" || echo "$0")")"
IMO, that'll produce confusing output. "I ran foo.sh, but it's saying I'm running bar.sh!? Must be a bug!" Besides, one of the purposes of having differently-named symlinks is to provide different functionality based on the name it's called as (think gzip and gunzip on some platforms).
1 That is, to resolve symlinks such that when the user executes foo.sh which is actually a symlink to bar.sh, you wish to use the resolved name bar.sh rather than foo.sh.
# ------------- SCRIPT ------------- #
#!/bin/bash
echo
echo "# arguments called with ----> ${#} "
echo "# \$1 ----------------------> $1 "
echo "# \$2 ----------------------> $2 "
echo "# path to me ---------------> ${0} "
echo "# parent path --------------> ${0%/*} "
echo "# my name ------------------> ${0##*/} "
echo
exit
# ------------- CALLED ------------- #
# Notice on the next line, the first argument is called within double,
# and single quotes, since it contains two words
$ /misc/shell_scripts/check_root/show_parms.sh "'hello there'" "'william'"
# ------------- RESULTS ------------- #
# arguments called with ---> 'hello there' 'william'
# $1 ----------------------> 'hello there'
# $2 ----------------------> 'william'
# path to me --------------> /misc/shell_scripts/check_root/show_parms.sh
# parent path -------------> /misc/shell_scripts/check_root
# my name -----------------> show_parms.sh
# ------------- END ------------- #
With bash >= 3 the following works:
$ ./s
0 is: ./s
BASH_SOURCE is: ./s
$ . ./s
0 is: bash
BASH_SOURCE is: ./s
$ cat s
#!/bin/bash
printf '$0 is: %s\n$BASH_SOURCE is: %s\n' "$0" "$BASH_SOURCE"
$BASH_SOURCE gives the correct answer when sourcing the script.
This however includes the path so to get the scripts filename only, use:
$(basename $BASH_SOURCE)
If the script name has spaces in it, a more robust way is to use "$0" or "$(basename "$0")" - or on MacOS: "$(basename \"$0\")". This prevents the name from getting mangled or interpreted in any way. In general, it is good practice to always double-quote variable names in the shell.
If you want it without the path then you would use ${0##*/}
To answer Chris Conway, on Linux (at least) you would do this:
echo $(basename $(readlink -nf $0))
readlink prints out the value of a symbolic link. If it isn't a symbolic link, it prints the file name. -n tells it to not print a newline. -f tells it to follow the link completely (if a symbolic link was a link to another link, it would resolve that one as well).
I've found this line to always work, regardless of whether the file is being sourced or run as a script.
echo "${BASH_SOURCE[${#BASH_SOURCE[#]} - 1]}"
If you want to follow symlinks use readlink on the path you get above, recursively or non-recursively.
The reason the one-liner works is explained by the use of the BASH_SOURCE environment variable and its associate FUNCNAME.
BASH_SOURCE
An array variable whose members are the source filenames where the corresponding shell function names in the FUNCNAME array variable are defined. The shell function ${FUNCNAME[$i]} is defined in the file ${BASH_SOURCE[$i]} and called from ${BASH_SOURCE[$i+1]}.
FUNCNAME
An array variable containing the names of all shell functions currently in the execution call stack. The element with index 0 is the name of any currently-executing shell function. The bottom-most element (the one with the highest index) is "main". This variable exists only when a shell function is executing. Assignments to FUNCNAME have no effect and return an error status. If FUNCNAME is unset, it loses its special properties, even if it is subsequently reset.
This variable can be used with BASH_LINENO and BASH_SOURCE. Each element of FUNCNAME has corresponding elements in BASH_LINENO and BASH_SOURCE to describe the call stack. For instance, ${FUNCNAME[$i]} was called from the file ${BASH_SOURCE[$i+1]} at line number ${BASH_LINENO[$i]}. The caller builtin displays the current call stack using this information.
[Source: Bash manual]
Since some comments asked about the filename without extension, here's an example how to accomplish that:
FileName=${0##*/}
FileNameWithoutExtension=${FileName%.*}
Enjoy!
These answers are correct for the cases they state but there is a still a problem if you run the script from another script using the 'source' keyword (so that it runs in the same shell). In this case, you get the $0 of the calling script. And in this case, I don't think it is possible to get the name of the script itself.
This is an edge case and should not be taken TOO seriously. If you run the script from another script directly (without 'source'), using $0 will work.
Re: Tanktalus's (accepted) answer above, a slightly cleaner way is to use:
me=$(readlink --canonicalize --no-newline $0)
If your script has been sourced from another bash script, you can use:
me=$(readlink --canonicalize --no-newline $BASH_SOURCE)
I agree that it would be confusing to dereference symlinks if your objective is to provide feedback to the user, but there are occasions when you do need to get the canonical name to a script or other file, and this is the best way, imo.
this="$(dirname "$(realpath "$BASH_SOURCE")")"
This resolves symbolic links (realpath does that), handles spaces (double quotes do this), and will find the current script name even when sourced (. ./myscript) or called by other scripts ($BASH_SOURCE handles that). After all that, it is good to save this in a environment variable for re-use or for easy copy elsewhere (this=)...
You can use $0 to determine your script name (with full path) - to get the script name only you can trim that variable with
basename $0
if your invoke shell script like
/home/mike/runme.sh
$0 is full name
/home/mike/runme.sh
basename $0 will get the base file name
runme.sh
and you need to put this basic name into a variable like
filename=$(basename $0)
and add your additional text
echo "You are running $filename"
so your scripts like
/home/mike/runme.sh
#!/bin/bash
filename=$(basename $0)
echo "You are running $filename"
This works fine with ./self.sh, ~/self.sh, source self.sh, source ~/self.sh:
#!/usr/bin/env bash
self=$(readlink -f "${BASH_SOURCE[0]}")
basename=$(basename "$self")
echo "$self"
echo "$basename"
Credits: I combined multiple answers to get this one.
echo "$(basename "`test -L ${BASH_SOURCE[0]} \
&& readlink ${BASH_SOURCE[0]} \
|| echo ${BASH_SOURCE[0]}`")"
In bash you can get the script file name using $0. Generally $1, $2 etc are to access CLI arguments. Similarly $0 is to access the name which triggers the script(script file name).
#!/bin/bash
echo "You are running $0"
...
...
If you invoke the script with path like /path/to/script.sh then $0 also will give the filename with path. In that case need to use $(basename $0) to get only script file name.
Short, clear and simple, in my_script.sh
#!/bin/bash
running_file_name=$(basename "$0")
echo "You are running '$running_file_name' file."
Out put:
./my_script.sh
You are running 'my_script.sh' file.
Info thanks to Bill Hernandez. I added some preferences I'm adopting.
#!/bin/bash
function Usage(){
echo " Usage: show_parameters [ arg1 ][ arg2 ]"
}
[[ ${#2} -eq 0 ]] && Usage || {
echo
echo "# arguments called with ----> ${#} "
echo "# \$1 -----------------------> $1 "
echo "# \$2 -----------------------> $2 "
echo "# path to me ---------------> ${0} " | sed "s/$USER/\$USER/g"
echo "# parent path --------------> ${0%/*} " | sed "s/$USER/\$USER/g"
echo "# my name ------------------> ${0##*/} "
echo
}
Cheers
DIRECTORY=$(cd `dirname $0` && pwd)
I got the above from another Stack Overflow question, Can a Bash script tell what directory it's stored in?, but I think it's useful for this topic as well.
Here is what I came up with, inspired by Dimitre Radoulov's answer (which I upvoted, by the way).
script="$BASH_SOURCE"
[ -z "$BASH_SOURCE" ] && script="$0"
echo "Called $script with $# argument(s)"
regardless of the way you call your script
. path/to/script.sh
or
./path/to/script.sh
$0 will give the name of the script you are running. Create a script file and add following code
#!/bin/bash
echo "Name of the file is $0"
then run from terminal like this
./file_name.sh
To get the "realpath" of script or sourced scripts in all cases :
fullname=$(readlink $0) # Take care of symbolic links
dirname=${fullname%/*} # Get (most of the time) the dirname
realpath=$(dirname $BASH_SOURCE) # TO handle sourced scripts
[ "$realpath" = '.' ] && realpath=${dirname:-.}
Here is the bash script to generate (in a newly created "workdir" subdir and in "mytest" in current dir), a bash script which in turn will source another script, which in turm will call a bash defined function .... tested with many ways to launch them :
#!/bin/bash
##############################################################
ret=0
fullname=$(readlink $0) # Take care of symbolic links
dirname=${fullname%/*} # Get (most of the time) the dirname
realpath=$(dirname $BASH_SOURCE) # TO handle sourced scripts
[ "$realpath" = '.' ] && realpath=${dirname:-.}
fullname_withoutextension=${fullname%.*}
mkdir -p workdir
cat <<'EOD' > workdir/_script_.sh
#!/bin/bash
##############################################################
ret=0
fullname=$(readlink $0) # Take care of symbolic links
dirname=${fullname%/*} # Get (most of the time) the dirname
realpath=$(dirname $BASH_SOURCE) # TO handle sourced scripts
[ "$realpath" = '.' ] && realpath=${dirname:-.}
fullname_withoutextension=${fullname%.*}
echo
echo "# ------------- RESULTS ------------- #"
echo "# path to me (\$0)-----------> ${0} "
echo "# arguments called with ----> ${#} "
echo "# \$1 -----------------------> $1 "
echo "# \$2 -----------------------> $2 "
echo "# path to me (\$fullname)----> ${fullname} "
echo "# parent path(\${0%/*})------> ${0%/*} "
echo "# parent path(\$dirname)-----> ${dirname} "
echo "# my name ----\${0##*/}------> ${0##*/} "
echo "# my source -\${BASH_SOURCE}-> ${BASH_SOURCE} "
echo "# parent path(from BASH_SOURCE) -> $(dirname $BASH_SOURCE)"
echo "# my function name -\${FUNCNAME[0]}------> ${FUNCNAME[0]}"
echo "# my source or script real path (realpath)------------------> $realpath"
echo
[ "$realpath" = "workdir" ] || ret=1
[ $ret = 0 ] || echo "*******************************************************"
[ $ret = 0 ] || echo "*********** ERROR **********************************"
[ $ret = 0 ] || echo "*******************************************************"
show_params () {
echo
echo "# --- RESULTS FROM show_params() ---- #"
echo "# path to me (\$0)-----------> ${0} "
echo "# arguments called with ----> ${#} "
echo "# \$1 -----------------------> $1 "
echo "# \$2 -----------------------> $2 "
echo "# path to me (\$fullname)----> ${fullname} "
echo "# parent path(\${0%/*})------> ${0%/*} "
echo "# parent path(\$dirname)-----> ${dirname} "
echo "# my name ----\${0##*/}------> ${0##*/} "
echo "# my source -\${BASH_SOURCE}-> ${BASH_SOURCE} "
echo "# parent path(from BASH_SOURCE) -> $(dirname $BASH_SOURCE)"
echo "# my function name -\${FUNCNAME[0]}------> ${FUNCNAME[0]}"
echo "# my source or script real path (realpath)------------------> $realpath"
echo
[ "$realpath" = "workdir" ] || ret=1
[ $ret = 0 ] || echo "*******************************************************"
[ $ret = 0 ] || echo "*********** ERROR **********************************"
[ $ret = 0 ] || echo "*******************************************************"
}
show_params "$#"
EOD
cat workdir/_script_.sh > workdir/_side_by_side_script_sourced.inc
cat <<'EOD' >> workdir/_script_.sh
echo "# . $realpath/_side_by_side_script_sourced.inc 'hello there' 'william'"
. $realpath/_side_by_side_script_sourced.inc 'hello there' 'william'
[ $ret = 0 ] || echo "*******************************************************"
[ $ret = 0 ] || echo "*********** ERROR **********************************"
[ $ret = 0 ] || echo "*******************************************************"
EOD
chmod +x workdir/_script_.sh
[ -L _mytest_ ] && rm _mytest_
ln -s workdir/_script_.sh _mytest_
# ------------- CALLED ------------- #
called_by () {
echo '=========================================================================='
echo " Called by : " "$#"
echo '=========================================================================='
eval "$#"
}
called_by bash _mytest_
called_by ./_mytest_
called_by bash workdir/_script_.sh
called_by workdir/_script_.sh
called_by . workdir/_script_.sh
# ------------- RESULTS ------------- #
echo
echo
[ $ret = 0 ] || echo "*******************************************************"
[ $ret = 0 ] || echo "*********** ERROR **********************************"
[ $ret = 0 ] || echo "*******************************************************"
echo
[ $ret = 0 ] && echo ".... location of scripts (\$realpath) should always be equal to $realpath, for all test cases at date".
echo
# ------------- END ------------- #
echo "You are running $0"
somthing like this?
export LC_ALL=en_US.UTF-8
#!/bin/bash
#!/bin/sh
#----------------------------------------------------------------------
start_trash(){
ver="htrash.sh v0.0.4"
$TRASH_DIR # url to trash $MY_USER
$TRASH_SIZE # Show Trash Folder Size
echo "Would you like to empty Trash [y/n]?"
read ans
if [ $ans = y -o $ans = Y -o $ans = yes -o $ans = Yes -o $ans = YES ]
then
echo "'yes'"
cd $TRASH_DIR && $EMPTY_TRASH
fi
if [ $ans = n -o $ans = N -o $ans = no -o $ans = No -o $ans = NO ]
then
echo "'no'"
fi
return $TRUE
}
#-----------------------------------------------------------------------
start_help(){
echo "HELP COMMANDS-----------------------------"
echo "htest www open a homepage "
echo "htest trash empty trash "
return $TRUE
} #end Help
#-----------------------------------------------#
homepage=""
return $TRUE
} #end cpdebtemp
# -Case start
# if no command line arg given
# set val to Unknown
if [ -z $1 ]
then
val="*** Unknown ***"
elif [ -n $1 ]
then
# otherwise make first arg as val
val=$1
fi
# use case statement to make decision for rental
case $val in
"trash") start_trash ;;
"help") start_help ;;
"www") firefox $homepage ;;
*) echo "Sorry, I can not get a $val for you!";;
esac
# Case stop

Not able retrieve the key value from shell script

I am working on the shell script to read config properties from a .properties files, below is the sample config
RCTP_servername=test1
RCTP_databasename=test2
RCTP_portnumber=test3
RCTP_username=test4
RCTP_password=test5
i have written a shell script as below but it doesn't work could anyone please have look and guide me how to solve this
#building the keys based on environment
environment=RCTP
servername_key="$environment"_servername
databasename_key="$environment"_databasename
portnumber_key="$environment"_portnumber
username_key="$environment"_username
password_key="$environment"_username
#read the config.properties files
file=serverconfig.properties
if [ -f "$file" ]
then
echo "$file found."
while IFS='=' read -r key value
do
key=$(echo $key )
eval "${key}='${value}'"
done < "$file"
servername_value=${servername_key}
databasename_value=${databasename_key}
portnumber_value=${portnumber_key}
username_value=${username_key}
password_value=${password_key}
else
echo "$file not found."
fi
echo "$servername_value"
but am getting an below when i tried to run it, the error is ./test_script_fte.sh: line 23: ${servername_key}: bad substitution
The expected output is when echo $servername_value executed is test1
Though eval is not recommended most of the time, here is a solution that uses indirect-reference as
echo "${!servername_value}"
I have also tweaked the logic to source the properties file over using eval from your logic. With the complete script as below.
#!/bin/bash
#building the keys based on environment
environment=RCTP
servername_key="$environment"_servername
databasename_key="$environment"_databasename
portnumber_key="$environment"_portnumber
username_key="$environment"_username
password_key="$environment"_username
#read the config.properties files
file=serverconfig.properties
if [ -f "$file" ]
then
echo "$file found."
# sourcing the properties file in the current shell to fetch the values
source "$file"
servername_value=${servername_key}
databasename_value=${databasename_key}
portnumber_value=${portnumber_key}
username_value=${username_key}
password_value=${password_key}
else
echo "$file not found."
fi
echo "${!servername_value}"
echo "${!databasename_value}"
echo "${!portnumber_value}"
echo "${!username_value}"
echo "${!password_value}"
It seems you want to use the value of a variable as the name of another variable.
please replace your last line with followings
eval echo \"\$$servername_value\"

shell script if folder exist has incorrect result

I have this shell script, and the folder does exist, but it always have no as result?
#!/bin/bash
FOLDER=/Library/Application\ Support/ESET/esets
if [ -d “$FOLDER” ];
then
echo yes
else
echo no
fi
thanks!
if [ -d “$FOLDER” ];
The type of quote marks you're using are not valid for the shell. Use "$FOLDER" instead.

How to execute a file that is located in $PATH

I am trying to execute a hallo_word.sh that is stored at ~/bin from this script that is stored at my ~/Desktop. I have made both scripts executable. But all the time I get the problem message. Any ideas?
#!/bin/sh
clear
dir="$PATH"
read -p "which file you want to execute" fl
echo ""
for fl in $dir
do
if [ -x "$fl" ]
then
echo "executing=====>"
./$fl
else
echo "Problem"
fi
done
This line has two problems:
for fl in $dir
$PATH is colon separated, but for expects whitespace separated values. You can change that by setting the IFS variable. This changes the FIELD SEPARATOR used by tools like for and awk.
$fl contains the name of the file you want to execute, but you overwrite its value with the contents of $dir.
Fixed:
#!/bin/sh
clear
read -p "which file you want to execute" file
echo
IFS=:
for dir in $PATH ; do
if [ -x "$dir/$file" ]
then
echo "executing $dir/$file"
exec "$dir/$file"
fi
done
echo "Problem"
You could also be lazy and let a subshell handle it.
PATH=(whatever) bash command -v my_command
if [ $? -ne 0 ]; then
# Problem, could not be found.
else
# No problem
fi
There is no need to over-complicate things.
command(1) is a builtin command that allows you to check if a command exists.
The PATH value contains all the directories in which executable files can be run without explicit qualification. So you can just call the command directly.
#!/bin/sh
clear
# r for raw input, e to use readline, add a space for clarity
read -rep "Which file you want to execute? " fl || exit 1
echo ""
"$fl" || { echo "Problem" ; exit 1 ; }
I quote the name as it could have spaces.
To test if the command exists before execution use type -p
#!/bin/sh
clear
# r for raw input, e to use readline, add a space for clarity
read -rep "Which file you want to execute? " fl || exit 1
echo ""
type -p "$fq" >/dev/null || exit 1
"$fl" || { echo "Problem" ; exit 1 ; }

bash copy file to new desintation if it doesnt exists make a new directory

Hello i am currently optimizing some code i have and am now wondering why this snippet of code does not work.
what is supposed to happen is when i copy the file i have to type in a destination for the copy if i type a destination that doesn't exist then the script will create a directory and copy that file to it.
this is what i have and i am wondering why it is not working
echo "Current Directory "
ls -a;
echo -n "Please Enter file name to Copy: "
read fileToCopy
echo -n "Enter Destination for Copy: ~/ "
read location
if [ -d $location ]
then
cp $fileToCopy $location
echo "File Successfully Copied to ~/ $location "
elif [ !-d $location ]
then
mkdir $location
cp $fileToCopy $location
echo "$location was created and the File was Copied to It! "
echo -n "Press Enter to Continue: "
else
echo "That file Does Not Exist! "
fi
Two issues:
One:
elif [ !-d $location ]
You need a space between ! and -d.
Two:
Quote your variables.
It's always good to error check. What if the user didn't enter a directory name or a file to copy?
In shell, a null variable will cause an error in a statement like this:
if [ $dir -eq foo ]
then
…
fi
That's because the shell will directly substitute the value and then interpret the line. If $dir is null, the statement will be:
if [ -eq foo ]
then
…
fi
This isn't valid. If you had quotes around $dir:
if [ "$dir" -eq foo ]
then
…
fi
You'd get this:
if [ "" -eq foo ]
then
…
fi
Which is valid.
If you're using bash it's preferable to use the double square brackets:
if [[ $dir -eq foo ]]
then
…
fi
This is a special improved syntactic test that will handle null variables and variables with spaces without having to use quotes.
The ! is a special shell operator that negates the return value of a command/statement. For the shell to understand the operator, you must make sure there is white space on either side of it. Also test the output of your mkdir statement to make sure it worked. And use the -p parameter. This will create parent directories.
if [[ ! -d "$dir" ]]
then
if ! mkdir -p "$dir"
then
echo "Could not create dir '$dir'" 1>&2
exit 2
fi
fi
Note that I always put quotes around my variable and I use the if statement to test to see if my command succeeded or not. After all, the user might have tried to create a directory where I don't have write permission.
One more secret trick. You can use set -xv to turn on shell script debugging. This will print out each statement as written and then as the shell interprets it. To turn it off use set +xv.

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