Change output of only the first line in bash script

Here is my source :

TABLE;APGFPOLI;

And here is the output that i want :

01 APGFPOLI. 

So what i am trying to do is remove "TABLE" and add 01 before "APGFPOLI". I need to do it for the first line only. So i tried to do :

    #!/bin/bash

#Fichier Source
fichier="APGFPOLI.des.txt"

champAdd="05 "

if [[ -f "$fichier" ]]
then
    
    # read it
    sed -i '1 s/TABLE//' $fichier |sed -i 's/CHAR/PIC X/' $fichier | sed -E '/Numérique/s/;Numérique\s+([^;]*)/;PIC 9(\1)/' $fichier | while IFS=';' read -r nomChamp format libelle
    do
        echo \* $libelle
        echo $champAdd $nomChamp $format.
    done > test.txt
fi

As you can see, my first sed is supposed to remove TABLE but it dont work. i also do a echo for my others line but i’d like to echo this specific first line too.

Here is the output my bash gives me :

  *
05 TABLE APGFPOLI.

Here is my full source if it helps :

TABLE;APGFPOLI;
Contrat;CHAR(16);Numéro du contrat
Libelle;CHAR(30);Libellé du contrat
DtCreation;CHAR(8);Date de création
DtMaj;CHAR(8);Date de dernière MAJ
DtEffet;CHAR(8);Date d'effet adhésion
MotifAdh;CHAR(2);Motif d'adhésion
DtRadiation;CHAR(8);Date de radiation
DtEnrRad;CHAR(8);Date enregistrement radiat
MotifRad;CHAR(2);Motif de radiation
MtPrime;Numérique 8.2;Montant prime d'origine
DtEffetSusp;CHAR(8);Date d'effet de suspension
DtFinSusp;CHAR(8);Date de fin de suspension
MotifSusp;CHAR(2);Motif de suspension
DestBord;CHAR(1);Destinataire du bordereau
CdDest;CHAR(5);Code du destinataire
NivRupBord;CHAR(1);Niveau rupture bordereau
BordCETIP;CHAR(1);Bordereau CTIP
EnvBordNom;CHAR(1);Envoi bordereau nominatif
Indice;CHAR(2);Indice appliqué
Echeance;CHAR(2);Echéance de l'indice (MM)
Effectif;CHAR(5);Effectif
CdRegr;CHAR(3);Code regroupement 1
CdGroupe;CHAR(3);Code regroupement 2
Periodicite;CHAR(1);Périodicité
Terme;CHAR(1);Terme
Produit;CHAR(6);Code produit affecté
Inspecteur;CHAR(5);Inspecteur
CleInsp;CHAR(1);Clé inspecteur
Filler;CHAR(6);Filler

>Solution :

You generally don’t want to run sed -i on the same file more than once.

Your entire task can be rephrased into just

sed -i '1s/TABLE/01 /' APGFPOLI.des.txt

If the replacement string should come from a shell variable, you need to use double quotes instead of single:

replacement="05"
sed -i "1s/TABLE/$replacement /" APGFPOLI.des.txt

If you want to keep your other tasks (which are not documented in the question) you can easily merge them into the same script. Remember, sed is a scripting language; you can feed in arbitrarily complex scripts (and some crazy people have even implemented desk calculators and Game of Life in sed scripts).

sed -i -E -e '1 s/TABLE/01 /' -e 's/CHAR/PIC X/' \
          -e '/Numérique/s/;Numérique\s+([^;]*)/;PIC 9(\1)/' APGFPOLI.des.txt