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Task 1:

If the Time is AM, print "It is Morning". If it is PM, print "It is not morning".

Task 2:

Given 2 arguments passed to the script.

Validate that 2 arguments have been submitted. If three arguments have not been provided, print "Must Supply 2 Arguments" and exit the script

• Argument 1: Should be a directory (needs validated). If this does not exist, print "Directory: directory, does not exist" and exit the script
• Argument 2: Should be a file (needs validated). If this does not exist, print "File: filename, does not exist" and exit the script.

If all arguments are valid, print "Given valid: filename and directory"

这就是我目前所拥有的

echo "James DuBois: 555555 - Task 1"
TIME=$(date "+%H")
if [ $TIME -lt 12 ]; then
    echo "morning"
else
    echo "not morning"
fi

echo "Task 2"

[ -d "$1" ] || exit
[ -d "$2" ] || exit
[ $# == 2 ] || exit

echo "arg1: $1"
echo "arg2: $2"

Answer 1

James，BASH 是一个美妙、灵活的 shell。它有它的缺点，但如果你需要做任何与 Linux 系统管理等有关的事情，你可以在 bash 中完成。您的任务是熟悉使用条件表达式(测试)。几乎所有您需要的东西都有测试。这就是为什么我向您指出 man bash 的条件表达式部分。

您的第二个任务需要输入文件名，以便您可以对其进行测试。我认为它旨在作为参数传递给您的脚本(称为位置参数)。这是进行测试的一种方法。 注意:为了您的利益，我特意交换了输出例程echo和printf(printf更加健壮)。请查看以下内容，让我知道您有什么问题:

#!/bin/bash
# My first script
#
#  echo & printf are used at random below -- intentionally
#

[ -z $1 ] && {  # validate at least 1 argument given on command line
    printf "error: insufficient input. usage:  %s filename\n" "${0##*/}"
    exit 1
}

printf "\nJames DuBois: 5555555\n\n  Task 1\n\n"
TIME=$(date "+%H")

## test for time of date: morning/not morning
if [ $TIME -lt 12 ]; then
    printf " morning - time for coffee\n"
else
    echo " not morning - time for scotch"
fi

echo -e "\n  Task 2\n"

printf "Testing whether '%s' is a valid file.\n\n" "$1"

## test for file using compound commands
[ -f "$1" ] && echo -e " file found: '$1'\n" || printf " file not found: '%s'\n\n" "$1"

echo -e "Second test whether '$1' is a valid file.\n"

## test for file using if; then; else; fi
if [ -f "$1" ]; then
    printf " file found: '%s'\n\n" "$1"
else
    echo -e " file not found: '$1'\n"
fi

exit 0

使用/输出

$ bash ~/scr/tmp/stack/morningfile.sh
error: insufficient input. usage:  morningfile.sh filename

$ bash ~/scr/tmp/stack/morningfile.sh mtrx_simple_dyn.c

James DuBois: 5555555

  Task 1

 not morning - time for scotch

  Task 2

Testing whether 'mtrx_simple_dyn.c' is a valid file.

 file found: 'mtrx_simple_dyn.c'

Second test whether 'mtrx_simple_dyn.c' is a valid file.

 file found: 'mtrx_simple_dyn.c'

$ bash ~/scr/tmp/stack/morningfile.sh dog.c

James DuBois: 5555555

  Task 1

 not morning - time for scotch

  Task 2

Testing whether 'dog.c' is a valid file.

 file not found: 'dog.c'

Second test whether 'dog.c' is a valid file.

 file not found: 'dog.c'