CODEWITHSUNDEEP
bashkey-value
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Elliptical view

Reputation: 3812

In bash extract select properties from a standard property file to a single delimited line?

In bash:

1) For a given groupname of interest, and
2) a list of keys of interest, for which we want a table of values, for this groupname,
3) read in a set of files, like those in /usr/share/applications (see simplified example below),
4) and produce a delimited table, with one line per file, and one field for each given key.

EXAMPLE

inputs

We want only the values of the Name and Exec keys, from only [Desktop Entry] groups, and from one or more files, like these:

[Desktop Entry]
Name=Root
Comment=Opens
Exec=e2

..

[Desktop Entry]
Comment=Close
Name=Root2

output

Two lines, one per input file, each in a delimited <Name>,<Exec> format, ready for import into a database:

Root,e2
Root2,

Each input file is:

[Forgive me if I am asking for a solution to an old problem, but I can't seem to find a good, quick bash way, to do this. Yes, I could code it up with some while and read loops, etc... but surely it's been done before.]

Similar to this Q but more general answer wanted.

Upvotes: 0

Views: 232

Answers (1)

tshiono
tshiono

Reputation: 22042

If awk is your option, would you please try the following:

awk -v RS="[" -v FS="\n" '{     # split the file into records on "["
                                # and split the record into fields on "\n"
    name = ""; exec = ""        # reset variables
    if ($1 == "Desktop Entry]") {
                                # if the groupname matches
        for (i=2; i<=NF; i++) { # loop over the fields (lines) of "key=value" pairs
            if (sub(/^Name=/, "", $i)) name = $i
                                # the field (line) starts with "Name="
            else if (sub(/^Exec=/, "", $i)) exec = $i
                                # the field (line) starts with "Exec="
        }
        print name "," exec
    }
}' file

You can feed multiple files as file1 file2 file3, dir/file* or whatever.

Upvotes: 2

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