I want to know how to write in bash an if statement with select command that echo a prompt error in case non correct option is given.
"The $strings variable is a column of strings."
menu() {
strings=$(echo "$(awk -F'[][]' '{ print $(2) }' file | awk NF)")
select string in $strings
do
if [[ "$string" MATCH ANY "${strings[#]}" ]]
then
echo "you've selected $account"
break
else
echo "Please, select one of the given options." && sleep 2
clear && menu
fi
done
}
I tried with:
if [[ "$string" =~ "${strings[#]} ]]
But does not work.
Can someone help me?
Thank you in advance.
I found the answer. It was as easy as not trying to compare with anything else, like this:
menu() {
strings=$(echo "$(awk -F'[][]' '{ print $(2) }' file | awk NF)")
select string in $strings
do
if [[ "$string" ]]
then
echo "you've selected $account"
break
else
echo "Please, select one of the given options." && sleep 2
clear && menu
fi
done
}
In your code you are missing the closing quote on your if.
it should be:
if [[ "$string" =~ "${strings[#]}" ]]
Related
I have this variable:
>echo $br_name
srxa wan-a1 br-wan3-xa1 0A:AA:DD:C1:F1:A3 ge-0.0.3 srxa wan-a2 br-wan3-xa2 0A:AA:DD:C1:F2:A3 ge-0.0.3
I am trying to create a conditional where it detects whether ge-0.0.3 is repeated more than 1 time in my variable $br_name
For example:
if [[ $br_name has ge-0.0.3 repeated more than one time ]]
then
echo "ge-0.0.3 is shown more than once"
else
:
fi
Bash's =~ is using extended RE.
[Bash-5.2] % check() { local s='(ge-0\.0\.3.*){2,}'; [[ "$1" =~ $s ]] && echo yes || echo no; }
[Bash-5.2] % check 'xxx'
no
[Bash-5.2] % check 'ge-0.0.3'
no
[Bash-5.2] % check 'ge-0.0.3 ge-0.0.3 '
yes
[Bash-5.2] % check 'ge-0.0.3 ge-0.0.3 ge-0.0.3 '
yes
You can use grep -o to print only the matched phrase. Also use -F to make sure that it matches literal characters instead of a regex where . and - are special
if [[ $(echo "$br_name" | grep -Fo ge-0.0.3 | wc -l) -gt 1 ]]; then
echo "ge-0.0.3 is shown more than once"
else
echo "only once"
fi
For more complex patterns of course you can drop -F and write a proper regex for grep
simple word
If your word would be "easy", you can detect the occurrences count with:
echo "123 123 123" | sed "s/123 /123\n/g" | wc -l
In which the word is replace for the same but with \n and then wc count the lines
or you can try one of these:
Count occurrences of a char in a string using Bash
How to count number of words from String using shell
complex
Since your word is "complex" or you will want a pattern, you will need regex:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
https://linuxconfig.org/advanced-bash-regex-with-examples
script.sh
count=0
for word in $1; do
if [[ "$word" =~ .*ge-0\.0\.3.* ]]
then
count=$(($count+1))
fi
done
if [ "$count" -gt "1" ];
then
echo "ge-0.0.3 is shown more than once"
else
if [ "$count" -eq "0" ];
then
echo "ge-0.0.3 is not shown"
else
echo "ge-0.0.3 is shown once"
fi
fi
execution
bash script.sh "srxa wan-a1 br-wan3-xa1 0A:AA:DD:C1:F1:A3 ge-0.0.3 srxa wan-a2 br-wan3-xa2 0A:AA:DD:C1:F2:A3 ge-0.0.3"
grep
With grep you can get the ocurrence count
ocurrences=( $(grep -oE '(ge-0\.0\.3)' <<<$1) )
ocurrences_count=${#ocurrences[*]}
echo $ocurrences_count
Assuming you want to do a literal string match on whole words, not substrings, then this might be what you want:
$ if (( $(grep -oFw 'ge-0.0.3' <<<"$br_name" | wc -l) > 1 )); then echo 'yes'; else echo 'no'; fi
yes
I have a flat file called items that I want to populate a select but I want to be able to choose multiple items at one time.
contents of items file:
cat 1
dog 1
pig 1
cherry 2
apple 2
Basic script:
#!/bin/bash
PS3=$'\n\nSelect the animals you like: '
options=$(grep '1' items|grep -v '^#' |awk '{ print $1 }')
select choice in $options
do
echo "you selected: $choice"
done
exit 0
The way it flows now is I can only select one option at at time. I'd like to be able to answer 1,3 or 1 3 and have it respond "you selected: cat pig"
Thank you,
Tazmarine
I can offer a somewhat different approach that uses a different selection prompt style. Here's a bash function that allows user to select multiple options with arrow keys and Space, and confirm with Enter. It has a nice menu-like feel. I wrote it with the help of https://unix.stackexchange.com/a/415155. It can be called like this:
multiselect result "Option 1;Option 2;Option 3" "true;;true"
The result is stored as an array in a variable with the name supplied as the first argument. Last argument is optional and is used for making some options selected by default. It looks like this:
function prompt_for_multiselect {
# little helpers for terminal print control and key input
ESC=$( printf "\033")
cursor_blink_on() { printf "$ESC[?25h"; }
cursor_blink_off() { printf "$ESC[?25l"; }
cursor_to() { printf "$ESC[$1;${2:-1}H"; }
print_inactive() { printf "$2 $1 "; }
print_active() { printf "$2 $ESC[7m $1 $ESC[27m"; }
get_cursor_row() { IFS=';' read -sdR -p $'\E[6n' ROW COL; echo ${ROW#*[}; }
key_input() {
local key
IFS= read -rsn1 key 2>/dev/null >&2
if [[ $key = "" ]]; then echo enter; fi;
if [[ $key = $'\x20' ]]; then echo space; fi;
if [[ $key = $'\x1b' ]]; then
read -rsn2 key
if [[ $key = [A ]]; then echo up; fi;
if [[ $key = [B ]]; then echo down; fi;
fi
}
toggle_option() {
local arr_name=$1
eval "local arr=(\"\${${arr_name}[#]}\")"
local option=$2
if [[ ${arr[option]} == true ]]; then
arr[option]=
else
arr[option]=true
fi
eval $arr_name='("${arr[#]}")'
}
local retval=$1
local options
local defaults
IFS=';' read -r -a options <<< "$2"
if [[ -z $3 ]]; then
defaults=()
else
IFS=';' read -r -a defaults <<< "$3"
fi
local selected=()
for ((i=0; i<${#options[#]}; i++)); do
selected+=("${defaults[i]}")
printf "\n"
done
# determine current screen position for overwriting the options
local lastrow=`get_cursor_row`
local startrow=$(($lastrow - ${#options[#]}))
# ensure cursor and input echoing back on upon a ctrl+c during read -s
trap "cursor_blink_on; stty echo; printf '\n'; exit" 2
cursor_blink_off
local active=0
while true; do
# print options by overwriting the last lines
local idx=0
for option in "${options[#]}"; do
local prefix="[ ]"
if [[ ${selected[idx]} == true ]]; then
prefix="[x]"
fi
cursor_to $(($startrow + $idx))
if [ $idx -eq $active ]; then
print_active "$option" "$prefix"
else
print_inactive "$option" "$prefix"
fi
((idx++))
done
# user key control
case `key_input` in
space) toggle_option selected $active;;
enter) break;;
up) ((active--));
if [ $active -lt 0 ]; then active=$((${#options[#]} - 1)); fi;;
down) ((active++));
if [ $active -ge ${#options[#]} ]; then active=0; fi;;
esac
done
# cursor position back to normal
cursor_to $lastrow
printf "\n"
cursor_blink_on
eval $retval='("${selected[#]}")'
}
You can not do that as such, but you can always record each individual selection:
#!/bin/bash
PS3=$'\n\nSelect the animals you like: '
options=$(grep '1' items|grep -v '^#' |awk '{ print $1 }')
# Array for storing the user's choices
choices=()
select choice in $options Finished
do
# Stop choosing on this option
[[ $choice = Finished ]] && break
# Append the choice to the array
choices+=( "$choice" )
echo "$choice, got it. Any others?"
done
# Write out each choice
printf "You selected the following: "
for choice in "${choices[#]}"
do
printf "%s " "$choice"
done
printf '\n'
exit 0
Here's an example interaction:
$ ./myscript
1) cat
2) dog
3) pig
4) Finished
Select the animals you like: 3
pig, got it. Any others?
Select the animals you like: 1
cat, got it. Any others?
Select the animals you like: 4
You selected the following: pig cat
If you instead want to be able to write 3 1 on the same line, you'll have to make your own menu loop with echo and read
This is what I came up with. This seems to works as I want. I want the final output to be comma separated:
#!/bin/bash
newarray=(all $(grep '1' items|grep -v '^#' |awk '{ print $1 }'))
options() {
num=0
for i in ${newarray[#]}; do
echo "$num) $i"
((num++))
done
}
getanimal() {
while [[ "$show_clean" =~ [A-Za-z] || -z "$show_clean" ]]; do
echo "What animal do you like: "
options
read -p 'Enter number: ' show
echo
show_clean=$(echo $show|sed 's/[,.:;]/ /g')
selected=$(\
for s in $show_clean; do
echo -n "\${newarray[${s}]},"
done)
selected_clean=$(echo $selected|sed 's/,$//')
done
eval echo "You selected $selected_clean"
}
getanimal
exit 0
I want an if/then statement in Bash and I can't seem to get it to work. I would like to say "If the line begins with > character, then do this, else do something else".
I have:
while IFS= read -r line
do
if [[$line == ">"*]]
then
echo $line'first'
else
echo $line'second'
fi
done
But it isn't working.
I also tried to escape the ">" by saying:
if [[$line == ^\>*]]
Which didn't work either.
Both ways I am getting this error:
line 27: [[>blah: command not found
Suggestions?
Spaces are needed inside [[ and ]] as follows:
if [[ "$line" == ">"* ]]; then
echo "found"
else
echo "not found"
fi
This attempt attempt uses a regex:
line="> line"
if [[ $line =~ ^\> ]] ; then
echo "found"
else
echo "not found"
fi
This one uses a glob pattern:
line="> line"
if [[ $line == \>* ]] ; then
echo "found"
else
echo "not found"
fi
Spacing is important.
$ [[ ">test" == ">"* ]]; echo $?
0
$ [[ "test" == ">"* ]]; echo $?
1
if grep -q '>' <<<$line; then
..
else
..
fi
using grep is much better :)
Can anyone see whats wrong here? If I put X|9 in lan.db (or any db in this directory) and run the following code, the IF statement does not work. It's weird! if you echo $LINE, it is indeed pulling X|9 out of lan.db (or any db in this directory) and setting it equal to LINE, but it wont do the comparison.
DBREGEX="^[0-9]|[0-9]$"
shopt -s nullglob
DBARRAY=(databases/*)
i=0
for i in "${!DBARRAY[#]}"; do
cat ${DBARRAY[$i]} | grep -v \# | while read LINE; do
echo "$LINE" (Whats weird is that LINE DOES contain X|9)
if [[ !( $LINE =~ $DBREGEX ) ]]; then echo "FAIL"; fi
done
done
If however I just manually sent LINE="X|9" the same code (minus the while) works fine. ie LINE=X|9 fails, but LINE=9|9 succeeds.
DBREGEX="^[0-9]|[0-9]$"
Comment shopt -s nullglob
Comment DBARRAY=(databases/*)
Comment i=0
Comment for i in "${!DBARRAY[#]}"; do
Comment cat ${DBARRAY[$i]} | grep -v \# | while read LINE; do
LINE="X|9"
if [[ !( $LINE =~ $DBREGEX ) ]]; then echo "FAIL"; fi
Comment done
Comment done
* UPDATE *
UGH I GIVE UP
Now not even this is working...
DBREGEX="^[0-9]|[0-9]$"
LINE="X|9"
if [[ ! $LINE =~ $DBREGEX ]]; then echo "FAIL"; fi
* UPDATE *
Ok, so it looks like I have to escape |
DBREGEX="^[0-9]\|[0-9]$"
LINE="9|9"
echo "$LINE"
if [[ ! $LINE =~ $DBREGEX ]]; then echo "FAIL"; fi
This seems to work ok again
| has a special meaning in a regular expression. ^[0-9]|[0-9]$ means "starts with a digit, or ends with a digit". If you want to match a literal vertical bar, backslash it:
DBREGEX='^[0-9]\|[0-9]$'
for LINE in 'X|9' '9|9' ; do
echo "$LINE"
if [[ ! $LINE =~ $DBREGEX ]] ; then echo "FAIL" ; fi
done
You don't need round brackets in regex evaluation. You script is also creating a sub shell and making a useless use of cat which can be avoided.
Try this script instead:
while read LINE; do
echo "$LINE"
[[ "$LINE" =~ $DBREGEX ]] && echo "PASS" || echo "FAIL"
done < <(grep -v '#' databases/lan.db)
I
write the following syntax (part of my ksh script)
to check if the first word of LINE=star
and the second word is car
[[ ` echo $LINE | awk '{print $1}' ` = star ]] && [[ ` echo $LINE | awk '{print $2}' ` = car ]] && print "match"
I need other simple smart and shorter solution then my syntax.
from awk,perl or sed(if it possible to use echo only once or better if we cant not use echo, because I need to save time to minimum)
can I get some ideas?
you don't actually need to call any external tools
set -f
set -- $LINE
case "$1 $2" in
"star car")
echo "match";;
esac
You don't need an external process at all:
[[ $LINE == *([ ])star+([ ])car?([ ]*) ]]
If you also need to extract the first word sometimes (warning, typed directly into the browser):
LINE=${LINE##+[ ]} # strip leading spaces
first_word=${LINE%%[ ]*}
if [[ $LINE = *[ ]* ]]; then
LINE_minus_first_word=${LINE##*+([ ])}
else
LINE_minus_first_word=''
fi
Add a tab inside the brackets if they may appear in $LINE.
set -o noglob
words=($LINE)
[[ "${words[0]} ${words[1]}" == "star car" ]] && print "match"
Edit:
Using ksh and Bash's regex matching (Bash >= version 3.2):
pattern='^[[:blank:]]*star[[:blank:]]+car([[:blank:]]+|$)'
[[ $LINE =~ $pattern ]] && print "match"
You can do:
[[ ` echo $LINE | awk '{printf("%s:%s",$1,$2)}'` = star:car ]] && print "match"