Explode a string into an array by tabulation

Question

I would have thought that was super simple, but here :

I want to "explode" a string into an array by tabulation and do a treatment into each string.

For information, the string comme from a mysql execution, so this string represent a row. Each field are separated by a tabulation (hence why I'm looking for exploding the string), can contain "\t" "\n" that I want to be a real tabulation / feed line, and can contain "\r\n" that I want to be replaced by "\n".

I had this function that I thought did the job

function MySQL__Untreated_String_To_Treated_Array() {
    local pstr_untreated_string
    local ltstr_treated_string_list
    local lstr_treated_string
    
    # Initialisation
    pstr_untreated_string="$1"
    gtReturnFonction=()
    
    # String treatment
    while IFS=$'\t' read -r -a ltstr_treated_string_list; do  
        for lstr_treated_string in "${ltstr_treated_string_list[@]}"; do
            gtReturnFonction+=( "$(printf "%b" "$lstr_treated_string")" )
        done
    done < <(echo "$pstr_untreated_string" | sed 's/\r\\n/\\n/g' | sed 's/\r/\\n/g')
}

BUT if my input string have multiple consecutive tabulation, it will not appear. I didn't knew, but it seem to be the normal behavior.

Then I tried multiple answer/code, but to no avail.

What I want is :

input = ""
result = ( "" )

input = "\t"
result = ( "" "" )

input = "\t\t"
result = ( "" "" "" )

And ultimatly

input = "\t_SECOND_FIELD_\t\t_FOURTH_\\\t_FIELD\t_FIFTH_\r\n_FIELD_\t"
result = ( "" "_SECOND_FIELD_" "" "_FOURTH_    _FIELD" "_FIFTH_
_FIELD_" "" )

I tried to use readarray, but failed too.

My bash version is 4.2.46 if this is important.

score 0 · Answer 1 · answered Nov 28 '22 at 19:27

As read can't parse properly, try this :

#!/bin/bash

function MySQL__Untreated_String_To_Treated_Array() {
    local pstr_untreated_string
    local ltstr_treated_string_list
    local lstr_treated_string

    # Initialisation
    pstr_untreated_string="$1"
    declare -n gtReturnFonction=$2

    # String treatment
    while IFS= read -r ltstr_treated_string_list; do
        while true; do
            lstr_treated_string="${ltstr_treated_string_list%%$'\t'*}"
            gtReturnFonction+=("$lstr_treated_string")
            new="${ltstr_treated_string_list#$lstr_treated_string$'\t'}"
            test "$new" = "$ltstr_treated_string_list" && break
            ltstr_treated_string_list="$new"
        done
    done < <(echo "$pstr_untreated_string" | sed 's/\r\\n/\\n/g' | sed 's/\r/\\n/g')
}

declare -a result
MySQL__Untreated_String_To_Treated_Array \
    $'\t_SECOND_FIELD_\t\t_FOURTH_\\t_FIELD\t_FIFTH_\r\n_FIELD_\t'\
    result
declare -p result

Output:

declare -a result=([0]="" [1]="_SECOND_FIELD_" [2]="" [3]="_FOURTH_\\t_FIELD" [4]="_FIELD_" [5]="")

Explode a string into an array by tabulation

1 Answers1