[SOLVED] Extract bin name from Cargo.toml using Bash

Issue

I am trying to extract bin names from from Cargo.toml using Bash, I enabled perl regular expression like this

First attempt

grep -Pzo '(?<=(^\[\[bin\]\]))\s*name\s*=\s*"(.*)"' ./Cargo.toml

The regular expression is tested at regex101 But got nothing

the Pzo options usage can be found here

Second attempt

grep -P (?<=(^[[bin]]))\n*\sname\s=\s*"(.*)" ./Cargo.toml

Still nothing

grep -Pzo '(?<=(^\[\[bin\]\]))\s*name\s*=\s*"(.*)"' ./Cargo.toml

Cargo.toml

[[bin]]
name = "acme1"
path = "bin/acme1.rs"

[[bin]]
name = "acme2"
path = "src/acme1.rs"

Solution

grep:

grep -A1 '^\[\[bin\]\]$' |
grep -Po '(?<=^name = ")[^"]*(?=".*)'

or if you can use awk, this is more robust

awk '
$1 ~ /^\[\[?[[:alnum:]]*\]\]?$/{
    if ($1=="[[bin]]" || $1=="[bin]") {bin=1}
    else {bin=0}
}
bin==1 &&
sub(/^[[:space:]]*name[[:space:]]*=[[:space:]]*/, "") {
    sub(/^"/, ""); sub(/".*$/, "")
    print
}' cargo.toml

Example:

$ cat cargo.toml
[[bin]]
name = "acme1"
path = "bin/acme1.rs"

[bin]
name="acme2"

[[foo]]
name = "nobin"

    [bin]
not_name = "hello"
name="acme3"
path = "src/acme3.rs"

[[bin]]
path = "bin/acme4.rs"
name = "acme4" # a comment

$ sh solution
acme1
acme2
acme3
acme4

Obviously, these are no substitute for a real toml parser.

Answered By - dan

Answer Checked By - Candace Johnson (WPSolving Volunteer)