Bash Shell脚本-对话框形式变量

Question

So, I just took up Shell Scripting and I'm developing an address book.

For the user to insert a contact I made this form:

form=$(dialog                                      \
    --title "INSERIR"                              \
    --form  ""                                     \
    0 0 0                                          \
    "Nome:"      1 1    "$nome"     1 10 20 0      \
    "Morada:"    2 1    "$morada"   2 10 20 0      \
    "Telefone:"  3 1    "$telefone"     3 10 20 0  \
    "E-Mail:"    4 1    "$mail"     4 10 20 0      \  
2>&1 1>&3)

And I want to insert those values through a MySQL query. I saw somewhere that I had to use, for instance:

form[$1]

In order to access the variable $nome. However, it was a comment from 2008. What is the easiest way to access those variables?

Thank you!

Answer 1

So, after a bit of tinkering I got what I was looking for. Here is the new form:

exec 3>&1

dialog                                             \
--separate-widget $'\n'                            \
--title "INSERIR"                                  \
--form ""                                          \
0 0 0                                              \
"Nome:"     1 1 "$nome"     1 10 30 0              \
"Morada:"       2 1     "$morada"       2 10 30 0  \
"Telefone:"     3 1     "$telefone" 3 10 30 0      \
"E-Mail:"       4 1     "$mail"         4 10 30 0  \
2>&1 1>&3 | {
    read -r nome
    read -r morada
    read -r telefone
    read -r mail

    #The rest of the script goes here
}

exec 3>&-

Answer 2

IFS=$'\n' read -r -d '' nome morada telefone mail < <( dialog ... )

Unlike dialog ... | { read; ... } dialog ... | { read; ... } dialog ... | { read; ... } (which scopes the variables which are read to a subshell), this approach puts dialog in the subshell, and your variables in the main shell -- much more convenient.

Answer 3

The question regarding the easiest way to access the result depends partly on whether the items might contain blanks. If the items can contain arbitrary data, then line-oriented output (the default) seems the only way to go. If they are more constrained, eg, not containing some readily-used punctuation character which can be used as a delimiter, then that makes it simpler.

The manual page mentions an option (and alias) which can be used to do this:

--separator string

--output-separator string

Specify a string that will separate the output on dialog's output from checklists, rather than a newline (for --separate-output ) or a space. This applies to other widgets such as forms and editboxes which normally use a newline.

For example, if the data does not include a : (colon), then you could use the option

--output-separator :

and get colon-separated values on a single line.

If there are no commas or quotes in the string, you could conceivably use

--output-separator \",\"

and embed the result directly in an SQL statement. However, commas occur more frequently than the other punctuation mentioned, so processing the form's output with sed is the most likely way one might proceed.

Answer 4

After several days looking for a way get those variables, here what I used, with your form:

nome=""
morada=""
telefone=""
mail=""

user_record=$(\
dialog                                             \
--separate-widget $'\n'                            \
--title "INSERIR"                                  \
--form ""                                          \
0 0 0                                              \
"Nome:"     1 1 "$nome"     1 10 30 0              \
"Morada:"       2 1     "$morada"       2 10 30 0  \
"Telefone:"     3 1     "$telefone" 3 10 30 0      \
"E-Mail:"       4 1     "$mail"         4 10 30 0  \
  3>&1 1>&2 2>&3 3>&- \
)
nome=$(echo "$user_record" | sed -n 1p)
morada=$(echo "$user_record" | sed -n 2p)
telefone=$(echo "$user_record" | sed -n 3p)
mail=$(echo "$user_record" | sed -n 4p)

echo $nome
echo $morada
echo $telefone
echo $mail

This way you can use those variables later on your script. Hope it helps others.

Answer 5

So, you can really just put the output into an array and deal with that. Avoids all the subshell / subprocess garbage. (Just trust on the flippy redirect, yeah, it's ugly but you're basically just subbing out stdin and swapping it back.) Not sure why that's been so elusive after 5 years, but hey. I guess it's cool to be obscure.

response=$(dialog                                  \
    --title "INSERIR"                              \
    --form  ""                                     \
    0 0 0                                          \
    "Nome:"      1 1    "$nome"     1 10 20 0      \
    "Morada:"    2 1    "$morada"   2 10 20 0      \
    "Telefone:"  3 1    "$telefone"     3 10 20 0  \
    "E-Mail:"    4 1    "$mail"     4 10 20 0      \  
    3>&1 1>&2 2>&3 3>&-)

#convert the space separated string to an array.. the madness!!
responsearray=($response)

echo ${responsearray[0]} #nome
echo $(responsearray[1]} #morada
echo ${responsearray[2]} #telefone
echo ${responsearray[3]} #mail

...and bob's your uncle.