Shell Programming and Scripting

#include<iostream>
#include<fstream>
#include<string>
#include<sstream>
using namespace std;
int main()
{
       	ofstream f;
	char file[50];
	int size;
	string st1 = "file", ext = ".txt";
	string fname, filename;
	for(int i=10009; i<10161; i++)
	{
		stringstream ss;
		ss << i;
		fname = ss.str();
		filename = fname.substr(1,fname.length()-1);
		filename = st1 + filename + ext;
		size = filename.size();
		for(int j=0; j<=size; j++) 	file[j]=filename[j];
		f.open(file);
		...
	}
	return 0;
}

[root@node2 ~]# bash --version | grep release
GNU bash, version 4.1.2(1)-release (x86_64-redhat-linux-gnu)
[root@node2 ~]# echo {0009..0161} | xargs -n 15
0009 0010 0011 0012 0013 0014 0015 0016 0017 0018 0019 0020 0021 0022 0023
0024 0025 0026 0027 0028 0029 0030 0031 0032 0033 0034 0035 0036 0037 0038
0039 0040 0041 0042 0043 0044 0045 0046 0047 0048 0049 0050 0051 0052 0053
0054 0055 0056 0057 0058 0059 0060 0061 0062 0063 0064 0065 0066 0067 0068
0069 0070 0071 0072 0073 0074 0075 0076 0077 0078 0079 0080 0081 0082 0083
0084 0085 0086 0087 0088 0089 0090 0091 0092 0093 0094 0095 0096 0097 0098
0099 0100 0101 0102 0103 0104 0105 0106 0107 0108 0109 0110 0111 0112 0113
0114 0115 0116 0117 0118 0119 0120 0121 0122 0123 0124 0125 0126 0127 0128
0129 0130 0131 0132 0133 0134 0135 0136 0137 0138 0139 0140 0141 0142 0143
0144 0145 0146 0147 0148 0149 0150 0151 0152 0153 0154 0155 0156 0157 0158
0159 0160 0161

seq -w 9 0161 | xargs -n 15

printf "%04d" 9

[root@node2 ~]# echo file{0009..0011}.txt
file0009.txt file0010.txt file0011.txt

num=8;
while [ $((num+=1)) -le 20 ]
do
 printf "file%04d.txt\n" $num
done

file0009.txt
file0010.txt
file0011.txt
file0012.txt
file0013.txt
file0014.txt
file0015.txt
file0016.txt
file0017.txt
file0018.txt
file0019.txt
file0020.txt

num=8;
while [ $((num+=1)) -le 20 ]
do
  filename='printf "file%04d.txt\n" $num'
  echo $filename
done