Vérifier si le fichier existe et s'il contient une chaîne spécifique

Question

Je souhaite vérifier si file2.sh existe et si un mot spécifique, poet fait partie du fichier. J'utilise grep pour créer la variable used_var.

#!/bin/ksh 

file_name=/home/file2.sh     
used_var=`grep "poet" $file_name`  

Comment puis-je vérifier si used_var a une certaine valeur?

Answer 1

test -e testera si un fichier existe ou non. La commande test renvoie une valeur nulle si le test réussit ou 1 sinon.

test peut être écrit comme test -e ou en utilisant []

[ -e "$file_name" ] && grep "poet" $file_name 

Sauf si vous avez réellement besoin de la sortie de grep vous pouvez tester la valeur de retour comme grep retourne 1 s'il n'y a pas matchs et zéro s'il sont tous.

En termes généraux, vous pouvez tester si une chaîne est non vide à l'aide [ "string" ] qui retournera 0 si non vide et 1 si elle est vide

Answer 2

Si vous avez le installé ou ksh binaire test a intégré correspondant fonction, vous pouvez l'utiliser pour effectuer vos vérifications. Habituellement /bin/[ est un lien symbolique vers test:

if [ -e "$file_name" ]; then 
    echo "File exists" 
fi 

if [ -z "$used_var" ]; then 
    echo "Variable is empty" 
fi 

Answer 3

if test -e "$file_name";then 
... 
fi 

if grep -q "poet" $file_name; then 
    .. 
fi 

Answer 4

Au lieu de stocker la sortie de grep dans une variable et vérifier ensuite si la variable est vide, vous pouvez le faire:

if grep -q "poet" $file_name 
then 
    echo "poet was found in $file_name" 
fi 

=============

Voici quelques tests couramment utilisés:

-d FILE 
      FILE exists and is a directory 
    -e FILE 
      FILE exists 
    -f FILE 
      FILE exists and is a regular file 
    -h FILE 
      FILE exists and is a symbolic link (same as -L) 
    -r FILE 
      FILE exists and is readable 
    -s FILE 
      FILE exists and has a size greater than zero 
    -w FILE 
      FILE exists and is writable 
    -x FILE 
      FILE exists and is executable 
    -z STRING 
      the length of STRING is zero 

Exemple:

if [ -e "$file_name" ] && [ ! -z "$used_var" ] 
then 
    echo "$file_name exists and $used_var is not empty" 
fi 

Answer 5

Vous devez utiliser le drapeau grep-q pour la sortie calme. Voir les pages de manuel ci-dessous:

homme Sortie grep:

General Output Control 

    -q, --quiet, --silent 
       Quiet; do not write anything to standard output. Exit immediately with zero status 
       if any match is found, even if an error was detected. Also see the -s or 
       --no-messages option. (-q is specified by POSIX.) 

Ce script KornShell (ksh) DEMOS la sortie est calme grep et une solution à votre question.

grepUtil.ksh:

#!/bin/ksh 

#Initialize Variables 
file=poet.txt 
var="" 
dir=tempDir 
dirPath="/"${dir}"/" 
searchString="poet" 

#Function to initialize variables 
initialize(){ 
    echo "Entering initialize" 
    echo "Exiting initialize" 
} 

#Function to create File with Input 
#Params: 1}Directory 2}File 3}String to write to FileName 
createFileWithInput(){ 
    echo "Entering createFileWithInput" 
    orgDirectory=${PWD} 
    cd ${1} 
    > ${2} 
    print ${3} >> ${2} 
    cd ${orgDirectory} 
    echo "Exiting createFileWithInput" 
} 

#Function to create File with Input 
#Params: 1}directoryName 
createDir(){ 
    echo "Entering createDir" 
    mkdir -p ${1} 
    echo "Exiting createDir" 
} 

#Params: 1}FileName 
readLine(){ 
    echo "Entering readLine" 
    file=${1} 
    while read line 
    do 
     #assign last line to var 
     var="$line" 
    done <"$file" 
    echo "Exiting readLine" 
} 
#Check if file exists 
#Params: 1}File 
doesFileExit(){ 
    echo "Entering doesFileExit" 
    orgDirectory=${PWD} 
    cd ${PWD}${dirPath} 
    #echo ${PWD} 
    if [[ -e "${1}" ]]; then 
     echo "${1} exists" 
    else 
     echo "${1} does not exist" 
    fi 
    cd ${orgDirectory} 
    echo "Exiting doesFileExit" 
} 
#Check if file contains a string quietly 
#Params: 1}Directory Path 2}File 3}String to seach for in File 
doesFileContainStringQuiet(){ 
    echo "Entering doesFileContainStringQuiet" 
    orgDirectory=${PWD} 
    cd ${PWD}${1} 
    #echo ${PWD} 
    grep -q ${3} ${2} 
    if [ ${?} -eq 0 ];then 
     echo "${3} found in ${2}" 
    else 
     echo "${3} not found in ${2}" 
    fi 
    cd ${orgDirectory} 
    echo "Exiting doesFileContainStringQuiet" 
} 
#Check if file contains a string with output 
#Params: 1}Directory Path 2}File 3}String to seach for in File 
doesFileContainString(){ 
    echo "Entering doesFileContainString" 
    orgDirectory=${PWD} 
    cd ${PWD}${1} 
    #echo ${PWD} 
    grep ${3} ${2} 
    if [ ${?} -eq 0 ];then 
     echo "${3} found in ${2}" 
    else 
     echo "${3} not found in ${2}" 
    fi 
    cd ${orgDirectory} 
    echo "Exiting doesFileContainString" 
} 

#----------- 
#---Main---- 
#----------- 
echo "Starting: ${PWD}/${0} with Input Parameters: {1: ${1} {2: ${2} {3: ${3}" 
#initialize #function call# 
createDir ${dir} #function call# 
createFileWithInput ${dir} ${file} ${searchString} #function call# 
doesFileExit ${file} #function call# 
if [ ${?} -eq 0 ];then 
    doesFileContainStringQuiet ${dirPath} ${file} ${searchString} #function call# 
    doesFileContainString ${dirPath} ${file} ${searchString} #function call# 
fi 
echo "Exiting: ${PWD}/${0}" 

grepUtil.ksh sortie:

user@foo /tmp 
$ ksh grepUtil.ksh 
Starting: /tmp/grepUtil.ksh with Input Parameters: {1: {2: {3: 
Entering createDir 
Exiting createDir 
Entering createFileWithInput 
Exiting createFileWithInput 
Entering doesFileExit 
poet.txt exists 
Exiting doesFileExit 
Entering doesFileContainStringQuiet 
poet found in poet.txt 
Exiting doesFileContainStringQuiet 
Entering doesFileContainString 
poet 
poet found in poet.txt 
Exiting doesFileContainString 
Exiting: /tmp/grepUtil.ksh