I have this simple command to check if a file exists:
if [ -f /tmp/file.txt ] ; then echo "yes" ; else echo "no" ; fi
If I run it direcly on terminal, it works (shows "yes" if the file exists and "no" if it doesn't). But I want to execute this command inside a .desktop file using it as a value to Exec key:
[Desktop Entry]
Version=1.0
Type=Application
Exec=if [ -f /tmp/file.txt ] ; then echo "yes" ; else echo "no" ; fi
StartupNotify=true
Terminal=false
Categories=Utility;X-XFCE;X-Xfce-Toplevel;
MimeType=x-scheme-handler/custom
Name=Custom Test
Comment=Custom
If I try to execute xdg-open custom:// I get custom://: error opening location: The specified location is not supported, but if I change Exec value to echo "yes" and execute xdg-open custom://, it shows yes on terminal.
What am I missing here?
You are trying to execute shell script coding in .desktop file which is not supported.
The reason why "echo yes" worked is .desktop executes the echo command with paramter as "yes" which is acceptable.
.desktop executes commands along with options and parameters. You can write the shell script code in a .sh file and mentioned it in Exec or Run the code using
Exec=sh -c "if [ -f /tmp/file.txt ] ; then echo 'yes' ; else echo 'no' ; fi"
Here .desktop executes "sh" with options and params
Try setting your Exec to:
bash -c 'if [ -f /tmp/file.txt ] ; then echo "yes" ; else echo "no" ; fi'
The 'if' command is a bash-builtin, not an external command.
Related
Something similar to this maybe:
#! /bin/bash
echo What is your name?
read name | cat > ~/Documents/file.txt
if [[ $name==Bob ]]
echo something
fi
The command creates an empty file on manjaro mint.
Your problem is that read doesn't create any output.
And you have a syntax error further down the line, it would be a good idea to put your script(s) through shellcheck.
#! /bin/bash
echo What is your name?
read -r name
echo "$name" > ~/Documents/file.txt
if [[ "$name" == "Bob" ]]; then
echo something
fi
as per http://linuxcommand.org/lc3_wss0150.php i am trying to run this script
#!/bin/bash
# Program to print a text file with headers and footers
TEMP_FILE=./printfile.txt
pr $1 > $TEMP_FILE
echo -n "Print file? [y/n]: "
read
if [ "$REPLY" = "y" ]; then
less $TEMP_FILE
fi
but when i run it via
./print_demo.bash
which is what it is saved as in my bin directory, it does not echo "Print file? [y/n]:" and also does not return the shell prompt. i have to ctrl^c to get it back.
That script is expecting input.
pr "$1" > $TEMP_FILE
The $1 represents the first argument from the command line
./print_demo.bash <printable_filename_here.txt>
I have the problem that my shell script is not acting exactly the same as my manual typing into a console. I am attempting to find and source some setup files in a shell script as follows:
#!/bin/bash
TURTLE_SHELL=bash
# source setup.sh from same directory as this file
_TURTLE_SETUP_DIR=$(builtin cd "`dirname "${BASH_SOURCE[0]}"`" > /dev/null && pwd)
. "$_TURTLE_SETUP_DIR/turtle_setup.sh"
This bash file calls a .sh file:
#!/bin/env sh
_TURTLE_ROS_SETUP_DIR=$_TURTLE_SETUP_DIR/../devel
if [ -z "$TURTLE_SHELL" ]; then
TURTLE_SHELL=sh
fi
if [ -d "$PX4_FIRMWARE_DIR/integrationtests" ]; then
if [ -f "$PX4_FIRMWARE_DIR/integrationtests/setup_gazebo_ros.bash" ]; then
. "$PX4_FIRMWARE_DIR/integrationtests/setup_gazebo_ros.bash" "$PX4_FIRMWARE_DIR"
fi
fi
if [ "$TURTLE_SHELL" = "bash" ]; then
if [ -f "$_TURTLE_ROS_SETUP_DIR/setup.bash" ]; then
source $_TURTLE_ROS_SETUP_DIR/setup.bash
fi
else
if [ "$TURTLE_SHELL" = "sh" ]; then
if [ -f "$_TURTLE_ROS_SETUP_DIR/setup.sh" ]; then
source $_TURTLE_ROS_SETUP_DIR/setup.sh
fi
fi
fi
The line in question is:
. "$PX4_FIRMWARE_DIR/integrationtests/setup_gazebo_ros.bash" "$PX4_FIRMWARE_DIR"
I have made sure that this code is actually running and that my environment variables are correct. If I run this command on the command line everything works well. However, the same is not true when the file is sourced via shell script. Why is this? Is there something different about the environment of a shell script that is different from a command line. Also, how can I fix this problem?
Edit:
I am sourcing either the .bash or the .sh scale, depending upon which shell I am using.
Edit 2:
I am sourcing this script. Thus, everything is run in my default bash terminal, and it is all run within the same terminal and not a terminal spawned from a child process. Why is the script not sourcing setup_gazebo_ros.bash within the current shell?
It's the same reason why you source the env script and not run it. When you run the script it runs in a new shell and the variables are not transferred back to the parent shell.
To illustrate
$ cat << ! > foo.sh
> export foo='FOO'
> !
$ chmod +x foo.sh
$ ./foo.sh
$ echo $foo
$ source ./foo.sh
$ echo $foo
FOO
I cannot find out how to see if a command is included in folders of environment variable PATH. I tried the command:
$type -t $command
but it doesn't work.
Can anyone help me?
This should work:
if [[ $(type -p command) ]]; then
echo "Found"
else
echo "Not Found"
fi
You can use -t too (See exceptions at bottom.).
Or (only testing the exit status with type):
if type command >& /dev/null; then
echo "Found"
else
echo "Not Found"
fi
Note: See exceptions at bottom.
Another solution (using hash):
if [[ ! $(hash command 2>&1) ]]; then
echo "Found"
else
echo "Not Found"
fi
Note: See exceptions at bottom.
Exceptions:
type command
type help
hash command
hash help
type -t command
type -t help
command and help are bash built-ins, they are not in any path in PATH environment variable. So the other methods except the first one (with -p option) will Print out Found for bash built-in commands which are not in any path in environment PATH variable.
Better use the first method (with -p option) if you only want to check if it's located in the paths in PATH environment variable.
Or if you want to use type -t then change the if statement like this:
if [[ $(type -t command) == file ]]; then
Do you mean looking at your path? Similar to:
$ set | grep PATH
Oh, now I understand. Checking for an executable in the path is fairly easy. I usually use something like the following:
## test for exe in PATH or exit
exevar="$(which exe 2>/dev/null)"
[ x = x$exevar ] && { echo "'exe' not in path"; exit 1; }
## exe in path, continue
echo "exevar = $exevar"
or use type -p to eliminate the call to which
## test for exe in PATH or exit
exevar="$(type -p exe 2>/dev/null)"
[ x = x$exevar ] && { echo "'exe' not in path"; exit 1; }
## exe in path, continue
echo "exevar = $exevar"
I have a build process, kicked off by Make, that executes a lot of child scripts.
A couple of these child scripts require root privileges, so instead of running everything as root, or everything as sudo, I'm trying to only execute the scripts that need to be as root, as root.
I'm accomplishing this like so:
execute_as_user() {
su "$1" -s /bin/bash -c "$2;exit \$?"
}
Arg $1 is the user to run the script as, arg $2 is the script.
Arg $1 is either root (gotten with: $(whoami) since everything is under sudo), or the current user's account (gotten with: $(logname))
The entire build is kicked off as:
sudo make all
Sample from the Makefile:
LOG="runtime.log"
ROTATE_LOG:=$(shell bash ./scripts/utils/rotate_log.sh)
system:
/bin/bash -c "time ./scripts/system.sh 2>&1 | tee ${LOG}"
My problem is... none of the child scripts are printing output to stdout. I believe it to be some sort of issue with an almost recursive call of su root... but I'm unsure. From my understanding, these scripts should already be outputting to stdout, so perhaps I'm mistaken where the output is going?
To be clear, I'm seeing no output in either the logfile nor displaying to the terminal (stdout).
Updating for clarity:
Previously, I just ran all the scripts either with sudo or just as the logged in user... which with my makefile above, would print to the terminal (stdout) and logfile. Adding the execute_as_user() function is where the issue cropped up. The scripts execute and build the project... just no display "that it's working" and no logs.
UPDATE
Here is some snippets:
system.sh snippet:
execute_script() {
echo "Executing as user $3: $2"
RETURN=$(execute_as_user $3 ${SYSTEM_SCRIPTS}/$2)
if [ ${RETURN} -ne ${OK} ]
then
error $1 $2 ${RETURN}
fi
}
build_package() {
local RETURN=0
case "$1" in
system)
declare -a scripts=(\
"rootfs.sh" \
"base_files.sh" \
"busybox.sh" \
"iana-etc.sh" \
"kernel.sh" \
"firmware.sh" \
"bootscripts.sh" \
"network.sh" \
"dropbear.sh" \
"wireless_tools.sh" \
"e2fsprogs.sh" \
"shared_libs.sh"
)
for SCRIPT_NAME in "${scripts[#]}"; do
execute_script $1 ${SCRIPT_NAME} $(logname)
echo ""
echo -n "${SCRIPT_NAME}"
show_status ${OK}
echo ""
done
# finalize base system
echo ""
echo "Finalizing base system"
execute_script $1 "finalize.sh" $(whoami)
echo ""
echo -n "finalize.sh"
show_status ${OK}
echo ""
# package into tarball
echo ""
echo "Packing base system"
execute_script $1 "archive.sh" $(whoami)
echo ""
echo -n "archive.sh"
show_status ${OK}
echo ""
echo ""
echo -n "Build System: "
show_status ${OK}
;;
*)
echo "$1 is not supported!"
exit 1
esac
}
sample child script executed by system.sh
cd ${CLFS_SOURCES}/
tar -xvjf ${PKG_NAME}-${PKG_VERSION}.tar.bz2
cd ${CLFS_SOURCES}/${PKG_NAME}-${PKG_VERSION}/
make distclean
RESPONSE=$?
if [ ${RESPONSE} -ne 0 ]
then
pkg_error ${RESPONSE}
exit ${RESPONSE}
fi
ARCH="${CLFS_ARCH}" make defconfig
RESPONSE=$?
if [ ${RESPONSE} -ne 0 ]
then
pkg_error ${RESPONSE}
exit ${RESPONSE}
fi
# fixup some bugs with musl-libc
sed -i 's/\(CONFIG_\)\(.*\)\(INETD\)\(.*\)=y/# \1\2\3\4 is not set/g' .config
sed -i 's/\(CONFIG_IFPLUGD\)=y/# \1 is not set/' .config
etc...
Here's the entire system.sh script:
https://github.com/SnakeDoc/LiLi/blob/master/scripts/system.sh
(i know the project is messy... it's a learn-as-you-go style project)
Previously, I just ran all the scripts either with sudo or just as the
logged in user... which with my makefile above, would print to the
terminal (stdout) and logfile. Adding the execute_as_user() function
is where the issue cropped up. The scripts execute and build the
project... just no display "that it's working" and no logs.
Just a guess, but you're probably not calling your function or not calling it properly:
execute_as_user() {
su "$1" -s /bin/bash -c "$2;exit \$?"
}
execute_as_user "$#"
I also noticed that you're not passing any argument to the script at all. Is this meant?
./scripts/system.sh ???