在作為電子郵件附件發送之前如何檢查文件是否可用

Question

如果 shell 找不到附件，shell 是否可以發送不帶附件的電子郵件？

我如何檢查附件的可用性，以便如果它不存在，它只是不發送電子郵件？

有什么標志可以使用嗎？

RESULT=passed
FILE=/path/data/file.csv
LOG=/another/path/data/log.log

echo "Hello Team, 
Please check the attached log and file." |mail -s "Result-$RESULT" -a $FILE -a $LOG somebody@sample.com

如果缺少此file.csv ，用戶將無法收到電子郵件。

Answer 1

您可以使用 test -f 來測試文件是否存在，因此：

test -f "$FILE" && echo "Hello Team, Please check the attached log and file." |mail -s "Result-$RESULT" -a $FILE -a $LOG somebody@sample.com

Answer 2

對任意數量的潛在附件的精選檢查：

#!/usr/bin/env bash

# Array of files to check and attach if available
declare -a file_list=(
  /path/data/file.csv
  /another/path/data/log.log
)

# Create an array for mail attachment arguments
declare -a attach_args=()

declare -- attached_files='' # Display actually attached files in the mail
declare -i attached_count=0  # Number of attached files

# Iterate attachments
for file in "${file_list[@]}"; do
  # If file exist, is not empty and is readable
  if [ -s "$file" ] && [ -r "$file" ]; then
    # Add the proper attachment arguments to the array
    attach_args+=(-a "$file")
    attached_count=$((attached_count + 1))
    # Add - filename and newline
    attached_files+="- ${file}"$'\n'
  fi
done

# Check to see if there is at least 1 attachment
if [ $attached_count -gt 0 ]; then
  mail -s "Result-$attached_count" "${attach_args[@]}" somebody@example.com <<EOF

Hello Team, 
Please check these ${attached_count} attached file(s):

${attached_files}
EOF
fi