检查getopts参数

Question

我正在编写一个脚本，将多个文件组合成一个文件。我不知道输入/输出文件的名称和有多少个输入文件，我决定使用-i标志读取输入文件，使用-o标志指定输出文件。

请注意，这只是读取输入/输出文件的第一步。我正在处理多种格式的输入文件: txt，xlsx，rtf，pdf。因此，单个cat f1 f2 f3 > outfile在我的情况下不起作用。

#!/bin/bash

# This script merge txt,xlsx,rtf,pdf files in pdf_input folder into a single pdf file and save the output 
# file to pdf_output folder


usage () {
  echo "Script usage:"
  echo "  $0 -i <input file1>,<input file2>,<input file3>,... -o <combined output file>"
  echo "  If you have multiple input files, the file names need to be seperated by ,"
  exit
}

while getopts ":i:o:" opt; do
    case $opt in
        i)
          echo "Input file string = $OPTARG "
          set -f
          IFS=',' # split on space characters
          array=($OPTARG) # use the split+glob operator
          ;;
        o)
          echo "Output file = $OPTARG"
          ;;
        h)
          usage
          exit 0
          ;;
        :)
          echo "Error: -${OPTARG} requires an argument."
          usage
          exit 1
          ;;
        *)
          usage
          exit 1
          ;;
    esac
done

echo "Number of input files: ${#array[@]}"
echo -n "Input files are:"
for i in "${array[@]}"; do
  echo -n " ${i} "
done

:)可以很好地检查空参数。但是，如果我同时使用-o和-i标志，我会得到意想不到的结果。有没有办法检查两个标志上的空参数？

#./pdf_merge.sh -i a,b,c,d -o out
Input file string = a,b,c,d
Output file = out
Number of input files: 4
Input files are: a  b  c  d

#./pdf_merge.sh -o
Error: -o requires an argument.
Script usage:
  ./pdf_merge.sh -i <input file1>,<input file2>,<input file3>,... -o <combined output file>
  If you have multiple input files, the file names need to be seperated by ,

#./pdf_merge.sh -i
Error: -i requires an argument.
Script usage:
  ./pdf_merge.sh -i <input file1>,<input file2>,<input file3>,... -o <combined output file>
  If you have multiple input files, the file names need to be seperated by ,

#./pdf_merge.sh -i -o
Input file string = -o
Number of input files: 1
Input files are: -o,

#./pdf_merge.sh -o -i
Output file = -i
Number of input files: 0

Answer 1

我在参数上添加了一个检查机制。这不是最干净的解决方案，但这是可行的。

while getopts ":i:o:" opt; do
    case $opt in
        i)
          echo "Input file string = $OPTARG "
          if [ "$OPTARG" == "-o" ]; then
            echo "Input error! You need to have at least one input file"
            usage
            exit 1
          fi
          set -f
          IFS=',' # split on space characters
          array=($OPTARG) # use the split+glob operator
          ;;
        o)
          echo "Output file = $OPTARG"
          if [ "$OPTARG" == "-i" ]; then
            echo "Input error! You need to specify an output file"
            usage
            exit 1
          fi
          ;;
        h)
          usage
          exit 0
          ;;
        :)
          echo "Error: -${OPTARG} requires an argument."
          usage
          exit 1
          ;;
        *)
          usage
          exit 1
          ;;
    esac
done

感谢大家的意见。