Compruebe si el archivo existe y si contiene una cadena específica

Question

Quiero comprobar si existe file2.sh y también si una palabra específica, poet es parte del archivo. Yo uso grep para crear la variable used_var.

#!/bin/ksh 

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

¿Cómo puedo comprobar si used_var tiene algún valor?

Answer 1

test -e comprobará si un archivo existe o no. El comando de prueba devuelve un valor cero si la prueba tiene éxito o 1 en caso contrario.

prueba se puede escribir ya sea como test -e o utilizando []

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

A menos que realmente necesita la salida de grep puede probar el valor de retorno como grep devolverá 1 si no hay coincidencias y cero si no hay alguno.

En términos generales, puede comprobar si una cadena es no vacío usando [ "string" ] que devolverá 0 si no vacío y 1 si está vacío

Answer 2

Si usted tiene la test instalado binario o ksh tiene un juego integrado función, puede usarlo para realizar sus comprobaciones. Por lo general, /bin/[ es un enlace simbólico a 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

En lugar de almacenar la salida de grep en una variable y luego comprobar si la variable está vacía, se puede hacer esto:

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

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

Aquí hay algunas pruebas de uso común:

-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 

Ejemplo:

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

Answer 5

Se debe utilizar la grep-q bandera para salida tranquila. Vea las páginas man a continuación:

hombre de salida 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.) 

Este script (ksh) KornShell Demos la grep salida tranquila y es una solución a su pregunta.

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 de salida:

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