I have many Yes/No answers in my script.
How can I create a function to minimize the size of my script?
I have the following:
function ask {
read -n 1 -r
if [[ $REPLY =~ ^[Yy]$ ]]
then
return 1;
else
exit
echo "Abort.."
fi
}
ask "Continue? [y/N] "
It works fine. But the Question "Continue? [y/N] is not displayed. How can I "transfer" this text to my function
You can use $1 variable:
function ask {
echo $1 # add this line
read -n 1 -r
if [[ $REPLY =~ ^[Yy]$ ]]
then
return 1;
else
exit
echo "Abort.."
fi
}
Edit: as noted by #cdarke, 'echo' call can be avoided thanks to '-p' switch in read:
# echo $1
# read -n 1 -r
read -n 1 -r -p "$1"
Related
I am new to shell, and my code takes two arguments from the user. I would like to confirm their arguments before running the rest of the code. I would like a y for yes to prompt the code, and if they type n for no, then the code will ask again for new arguments
Pretty much, if i type anything when I am asked to confirm, the rest of the code runs anyways. I tried inserting the rest of the code after the first then statement, but that didn't work either. I have also checked my code with ShellCheck and it all appears to be legal syntax. Any advice?
#!/bin/bash
#user passes two arguments
echo "Enter source file name, and the number of copies: "
read -p "Your file name is $1 and the number of copies is $2. Press Y for yes N for no " -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]
then
echo "cloning files...."
fi
#----------------------------------------REST OF CODE
DIR="."
function list_files()
{
if ! test -d "$1"
then echo "$1"; return;
fi
cd ... || $1
echo; echo "$(pwd)":; #Display Directory name
for i in *
do
if test -d "$i" #if dictionary
then
list_files "$i" #recursively list files
cd ..
else
echo "$i"; #Display File name
fi
done
}
if [ $# -eq 0 ]
then list_files .
exit 0
fi
for i in "$#*"
do
DIR=$1
list_files "$DIR"
shift 1 #To read next directory/file name
done
if [ ! -f "$1" ]
then
echo "File $1 does not exist"
exit 1
fi
for ((i=0; i<$2; i++))
do
cp "$1" "$1$i.txt"; #copies the file i amount of times, and creates new files with names that increment by 1
done
status=$?
if [ "$status" -eq 0 ]
then
echo 'File copied succeaful'
else
echo 'Problem copying'
fi
Moving the prompts into a while loop might help here. The loop will re-prompt for the values until the user confirms them. Upon confirmation, the target code will be executed and the break statement will terminate the loop.
while :
do
echo "Enter source file name:"
read source_file
echo "Number of copies"
read number_of_copies
echo "Your file name is $source_file and the number of copies is $number_of_copies."
read -p "Press Y for yes N for no " -n 1 -r
if [[ $REPLY =~ ^[Yy]$ ]]; then
echo "cloning files...."
break ### <<<---- terminate the loop
fi
echo ""
done
#----------------------------------------REST OF CODE
I have a password function that I borrowed from How do I echo stars (*) when reading password with read?
I tried to adapt it so that I can run through the function twice to do a password confirmation and then evaluate the 2 passwords to determine if they match but I seem to be missing some basics of how bash works in this case.
I tried replacing PASSWORD with $1 but kept getting command not found errors
passWord() {
unset PASSWORD
unset CHARCOUNT
stty -echo
CHARCOUNT=0
while IFS= read -p "$PROMPT" -r -s -n 1 CHAR; do
# Enter - accept password
if [[ $CHAR == $'\0' ]] ; then
break
fi
# Backspace
if [[ $CHAR == $'\177' ]] ; then
if [ $CHARCOUNT -gt 0 ] ; then
CHARCOUNT=$((CHARCOUNT-1))
PROMPT=$'\b \b'
PASSWORD="${PASSWORD%?}"
else
PROMPT=''
fi
else
CHARCOUNT=$((CHARCOUNT+1))
PROMPT='*'
PASSWORD+="$CHAR"
fi
done
stty echo; echo
${1}=${PASSWORD}
}
echo -n "Enter the password > "
passWord passOne
echo -n "Please re-enter the password > "
passWord passTwo
if [[ $passOne == $passTwo ]]; then
PASSWORD=$passOne
else
echo "Passwords did not match, please try again."
fi
Update
Here is the script with the latest updates
#!/bin/bash
passWord() {
unset password
local prompt char
stty -echo
charcount=0
while IFS= read -p "$prompt" -r -s -n 1 CHAR; do
# Enter - accept password
if [[ $char == $'\0' ]] ; then
break
fi
# Backspace
if [[ $char == $'\177' ]] ; then
if [ $charcount -gt 0 ] ; then
charcount=$((CHARCOUNT-1))
prompt=$'\b \b'
password="${password%?}"
else
prompt=''
fi
else
charcount=$((charcount+1))
prompt='*'
password+="$char"
fi
done
stty echo; echo
}
echo -n "Enter the password > "
passWord
pass1=$password
echo -n "Please re-enter the password > "
passWord
pass2=$password
if [[ "$pass1" == "$pass2" ]]; then
PassWord=$pass1
else
echo "Passwords did not match, please try again."
fi
You are missing a declaration of your shell.
Please add a shebang as the first line:
#!/bin/bash
The assignment of variables (the line ${1}=${PASSWORD}) doesn't work.
One way to solve it (not recomended) is to add eval:
eval "${1}=${PASSWORD}" # don't use quite risky.
But as that makes any input a security issue, you should use some other line.
One solution is to use declare (bash 4.2+):
declare -g "${1}=${PASSWORD}"
The -g is required (required and available since bash 4.2) to change General variables (not local to the function).
Or use printf (since bash 3.1):
printf -v "${1}" '%s' "${PASSWORD}"
Other than that, you should add a local command for variables used inside the function to avoid conflicts with external variables and should add a PROMPT='' just before the loop to avoid the printing of an initial asterisk when calling the function a second time.
It should be said that using variables in CAPS should be avoided. Variables in CAPS denote environment variables, the rest of variables use lower case to avoid conflicts.
I want to prompt to do something or not. And if a specific argument such as "-y" or "--yes" is passed I want to make the script non-interactive (force user answer).
if [ $# = 1 ] && [ "$1" = "-y" ]; then
# my code here
else
read -n 1 -p "¿Install this? [y/N] "
if [[ $REPLY =~ ^([Yy])$ ]]; then
# same code here
fi
fi
If I had to use a function I would like it to be something not to do with the code but with the test as I have a lot of this tests in the script.
function(argument)
{
if [ $# = 1 ] && [ "$1" = "-y" ]; then
return true
else
read -n 1 -p "$argument [y/N] "
if [[ $REPLY =~ ^([Yy])$ ]]; then
return true
fi
fi
}
if function("¿Install this?"); then
# my code here
fi
This function is wrong because it overrides the script's argument with the function call's argument.
install_maybe () {
echo $# $1
if [ $# = 1 ] && [ "$1" = "-y" ]; then
return 0
else
read -n 1 -p "$1 [y/N] "
if [[ $REPLY =~ ^[Yy]$ ]]; then
return 0
fi
fi
return 1
}
if install_maybe "Install everything?"; then
source "$DOTFILES/install/esential" "-y"
else source "$DOTFILES/install/esential"
fi
Simply define a flag in a variable that indicates the presence / absence of -y, the auto-confirmation option, among the command-line arguments, and pass that flag to your helper function as a 2nd argument:
#!/bin/bash
# Helper function to ensure that the user has confirmed the intent to proceed.
assertConfirmation() {
local promptMsg=$1 autoConfirm=$2
if (( autoConfirm )); then
return
else
read -n 1 -p "$promptMsg [y/N] "
printf '\n' # Output a newline, because none was appended to the user's keypress.
if [[ $REPLY =~ ^([Yy])$ ]]; then
return
fi
fi
# Getting here means: confirmation was not given - abort the script as a whole.
echo "Aborted." >&2 # Note how the message is sent to *stderr*.
exit 2 # Use a dedicated exit code to signal this condition.
}
# ... Code that performs proper parsing of command-line arguments,
# such as with getopts or GNU getopt, omitted for brevity.
# Here, I assume that the option to signal automatic confirmation
# is in $1, if provided.
[[ $1 == '-y' ]] && autoConfirm=1 || autoConfirm=0
# Call the helper function, which only returns if confirmation is
# either implied by the relevant command-line option or, in its absence,
# by the user confirming the intent to proceed interactively.
assertConfirmation "Install everything?" "$autoConfirm"
# Proceed...
echo "Installing..."
I seem to have this problem. This code breaks at line 119 in my script with bash associative arrays. I am sorry for the comments but I am kind to new to bash scripting. This is the code:
#!/bin/bash
# Aliases file
# Command usage: cpRecent/mvRecent -d {dirFrom},{dirTo} -n {numberofFiles} -e {editTheNames}
# Error codes
NO_ARGS="You need to pass in an argument"
INVALID_OPTION="Invaild option:"
NO_DIRECTORY="No directory found"
# Return values
fullpath=
directories=
numfiles=
interactive=
typeset -a files
typeset -A filelist
# Advise that you use relative paths
__returnFullPath(){
local npath
if [[ -d $1 ]]; then
cd "$(dirname $1)"
npath="$PWD/$(basename $1)"
npath="$npath/" #Add a slash
npath="${npath%.*}" #Delete .
fi
fullpath=${npath:=""}
}
__usage(){
wall <<End-Of-Message
________________________________________________
<cpRecent/mvRecent> -d "<d1>,<d2>" -n <num> [-i]
-d First flag: Takes two arguments
-n Second flag: Takes one argument
-i Takes no arguments. Interactive mode
d1 Directory we are reading from
d2 Directory we are writing to
num Number of files
________________________________________________
End-Of-Message
}
__processOptions(){
while getopts ":d:n:i" opt; do
case $opt in
d ) IFS=',' read -r -a directories <<< "$OPTARG";;
n ) numfiles=$OPTARG;;
i ) interactive=1;;
\? ) echo "$INVALID_OPTION -$OPTARG" >&2 ; return 1;;
: ) echo "$NO_ARGS"; __usage; return 1;;
* ) __usage; return 1;;
esac
done
}
__getRecentFiles(){
# Check some conditions
(( ${#directories[#]} != 2 )) && echo "$INVALID_OPTION Number of directories must be 2" && return 2
#echo ${directories[0]} ${directories[1]}
# Get the full paths of the directories to be read from/written to
__returnFullPath "${directories[0]}"
directories[0]="$fullpath"
__returnFullPath "${directories[1]}"
directories[1]="$fullpath"
if [[ -z ${directories[0]} || -z ${directories[1]} ]]; then
echo $NO_DIRECTORY
return 3
fi
[[ numfiles != *[!0-9]* ]] && echo "$INVALID_OPTION Number of files cannot be a string" && return 4
#numfiles=$(($numfiles + 0))
(( $numfiles == 0 )) && echo "$INVALID_OPTION Number of files cannot be zero" && return 4
local num="-"$numfiles""
# Get the requested files in directory(skips directories)
if [[ -n "$(ls -t ${directories[0]} | head $num)" ]]; then
# For some reason using local -a or declare -a does not seem to split the string into two
local tempfiles=($(ls -t ${directories[0]} | head $num))
#IFS=' ' read -r -a tempfiles <<< "$string"
#echo ${tempfiles[#]}
for index in "${!tempfiles[#]}"; do
echo $index ${tempfiles[index]}
[[ -f "${directories[0]}${tempfiles[index]}" ]] && files+=("${tempfiles[index]}")
done
fi
}
####################################
# The problem is this piece of code
__processLines(){
local name
local answer
local dirFrom
local dirTo
if [[ -n $interactive ]]; then
for (( i=0; i< ${#files[#]}; i++ )); do
name=${files[i]}
read -n 1 -p "Old name: $name. Do you wish to change the name(y/n)?" answer
[[ answer="y" ]] && read -p "Enter new name:" name
dirFrom="${directories[0]}${files[i]}"
dirTo="${directories[1]}$name"
fileslist["$dirFrom"]="$dirTo"
done
else
for line in $files; do
dirFrom="${directories[0]}$line"
echo $dirFrom # => /home/reclusiarch/Documents/test
dirTo="${directories[1]}$line"
echo $dirTo # => /home/reclusiarch/test
fileslist["$dirFrom"]="$dirTo" # This is the offending line
done
fi
}
###########################################################
cpRecent(){
__processOptions $*
__getRecentFiles
__processLines
for line in "${!filelist[#]}"; do
cp $line ${filelist[$line]}
done
echo "You have copied ${#fileList[#]} files"
unset files
unset filelist
return
}
mvRecent(){
__processOptions $*
__getRecentFiles
__processLines
for line in "${!filelist[#]}"; do
mv $line ${filelist[$line]}
done
echo "You have copied ${#fileList[#]} files"
unset files
unset filelist
return
}
cpRecent "$*"
I have tried a lot of things. To run the script,
$ bash -x ./testing.sh -d "Documents,." -n 2
But nothing seems to work:
The error is this(when using bash -x):
./testing.sh: line 119: /home/reclusiarch/Documents/test: syntax error: operand expected (error token is "/home/reclusiarch/Documents/test")
If I run that section on the command line, it works:
$ typeset -A filelist
$ filelist["/home/reclusiarch/Documents/test"]=/home/reclusiarch/test
$ echo ${filelist["/home/reclusiarch/Documents/test"]}
/home/reclusiarch/test
Thanks for your help!!
Edit: I intially pared down the script to the piece of offending code but that might make it not run. Again, if you want to test it, you could run the bash command given. (The script ideally would reside in the user's $HOME directory).
Edit: Solved (Charles Duffy solved it) It was a simple mistake of forgetting which name was which.
Your declaration is:
typeset -A filelist
However, your usage is:
fileslist["$dirFrom"]="$dirTo"
fileslist is not filelist.
I want to make a build chain script, and I don't want it to perform until the end if there are error during compilation.
It's the first time I write a more "elaborated" script in bash, and it just doesn't work:
it doesn't echo ERROR although I have lines with the word error in it
whatever the value of testError, the script just hangs in the line
this is the code:
testError=false
output=$(scons)
while read -r line; do
if [[ $line == .*[eE]rror.* ]] ; then echo 'ERROR' ; $testError = true ; fi #$testError = true fi
done
echo $testError
if $testError ; then exit ; fi;
... other commands
EDIT: Following all posters answers and Bash setting a global variable inside a loop and retaining its value -- Or process substituion for dummies and How do I use regular expressions in bash scripts?,
this is the final version of the code.
It works:
testError=false
shopt -s lastpipe
scons | while read -r line; do
if [[ $line =~ .*[eE]rror.* ]] ; then
echo -e 'ERROR'
testError=true
fi
echo -e '.'
done
if $testError ; then
set -e
fi
You set the value of testError in a subshell induced by your pipeline. When that subshell exits (at the end of the pipeline), any changes you made disappear. Try this:
while read -r line; do
if [[ $line == .*[eE]rror.* ]] ; then
echo -e 'ERROR'
testError=true
fi #$testError = true fi
done < <( scons )
or, if you don't want or can't use process substitution, use a temporary file
scons > tmp
while read -r line; do
if [[ $line == .*[eE]rror.* ]] ; then
echo -e 'ERROR'
testError=true
fi #$testError = true fi
done < tmp
This eliminates the pipeline, so the changes to testError persist after the while loop.
And, if your version of bash is new enough (4.2 or later), there is an option that allows the while loop at the end of a pipeline to execute in the current shell, not a subshell.
shopt -s lastpipe
scons | while read -r line; do
if [[ $line == .*[eE]rror.* ]] ; then
echo -e 'ERROR'
testError=true
fi #$testError = true fi
done
You should try
set -e
this stops the script to continue if a command exit with a non zero status
or better
error_case() { # do something special; }
trap 'echo >&2 "an error occurs"; error_case' ERR
this run error_case function each time a command exit with a non zero status
See http://mywiki.wooledge.org/BashFAQ/105
Another bug is that you have spaces in the assignment. And skip the $
$testError = true
should be
testError=true
EDIT
testerror is changed in the subshell. Try
testerror=$(
scons | while read -r line; do
if [[ $line == .*[eE]rror.* ]] ; then
echo true
fi #$testError = true fi
done
)
Are you trying to parse the output of scons?
This:
output=$(scons)
while read -r line; do
if [[ $line == .*[eE]rror.* ]] ; then
echo 'ERROR'
testError=true
fi
done
does not do that. Perhaps you want:
scons | while read -r line; do ... ; done
I answer also because other answers didn't notice: the use of regular expression should be done this way, using =~and not ==:
if [[ $line =~ .*[eE]rror.* ]] ; then
...
cf How do I use regular expressions in bash scripts?