• 判断变量
• 判断输入参数
• 直接通过变量判断
• 使用test判断
• 使用""判断
• pubmed下载
• 文件夹不存在则创建
• 文件存在则删除
• 参考

pid=$(jps | grep "bioinfo-0.0.1-SNAPSHOT.jar" | awk '{print $1}')

判断变量

read -p "input a word :" word
if  [ ! -n "$word" ] ;then
    echo "you have not input a word!"
else
    echo "the word you input is $word"
fi

判断输入参数

#!/bin/bash
if [ ! -n "$1" ] ;then
    echo "you have not input a word!"
else
    echo "the word you input is $1"
fi

直接通过变量判断

#!/bin/sh
para1=
if [ ! $para1 ]; then
  echo "IS NULL"
else
  echo "NOT NULL"
fi

使用test判断

#!/bin/sh
dmin=
if test -z "$dmin"
then
  echo "dmin is not set!"
else 
  echo "dmin is set !"
fi

使用""判断

#!/bin/sh
dmin=
if [ "$dmin" = "" ]
then
  echo "dmin is not set!"
else 
  echo "dmin is set !"
fi

pubmed下载

#!/usr/bin/env bash

Link="http://www.ncbi.nlm.nih.gov/pubmed/"
PMCLink="http://www.ncbi.nlm.nih.gov/pmc/articles/"
ID=(33719338 77777777)
for f in ${ID[@]};
do
    echo "${Link}${f}"
    PMCID=$(wget  --user-agent="Mozilla/5.0 (Windows NT 5.2; rv:2.0.1) Gecko/20100101 Firefox/4.0.1" \
    -l1 --no-parent ${Link}${f} -O - 2>/dev/null | grep -Po 'PMC\d+' | head -n 1)
    echo "$PMCID"
    if [ $PMCID ]; then
        wget  --user-agent="Mozilla/5.0 (Windows NT 5.2; rv:2.0.1) Gecko/20100101 Firefox/4.0.1" \
            -l1 --no-parent -A.pdf ${PMCLink}${PMCID}/pdf/ -O ${f}.pdf 2>/dev/null
    else
        echo "No PMC ID for $f"
    fi

done

#!/usr/bin/env bash

Link="http://www.ncbi.nlm.nih.gov/pubmed/"
PMCLink="http://www.ncbi.nlm.nih.gov/pmc/articles/"
# ID=(33719338 77777777)
PID=$1
if  ! test $PID ;then
    echo "please input PID!"
    exit
fi

OUT_NAME=$PID
if test $2; then
    OUT_NAME=$2
fi

echo "downlaod: ${Link}${PID} - ${OUT_NAME}"
PMCID=$(wget  --user-agent="Mozilla/5.0 (Windows NT 5.2; rv:2.0.1) Gecko/20100101 Firefox/4.0.1" \
-l1 --no-parent ${Link}${PID} -O - 2>/dev/null | grep -Po 'PMC\d+' | head -n 1)
echo "$PMCID"
if [ $PMCID ]; then
    wget  --user-agent="Mozilla/5.0 (Windows NT 5.2; rv:2.0.1) Gecko/20100101 Firefox/4.0.1" \
        -l1 --no-parent -A.pdf ${PMCLink}${PMCID}/pdf/ -O ${OUT_NAME}.pdf 2>/dev/null
else
    echo "No PMC ID for $PID"
fi

文件夹不存在则创建

if [ ! -d "/data/" ];then
  mkdir /data
  else
  echo "文件夹已经存在"
fi

文件存在则删除

if [ ! -f "/data/filename" ];then
  echo "文件不存在"
  else
  rm -f /data/filename
fi

参考

• shell 判断文件夹或文件是否存在