c語言顯示txt 并加入行号,《C語言及程式設計》實踐參考——帶行号顯示檔案

#include

#include

int main(int argc,char *argv[])

{

FILE *in;

char line[81];

int row;

if (argc<2) //對于指令行中參數個數有要求的程式，常用argc檢查參數是否夠用

{

printf("Usage: %s textfile \n",argv[0]);

exit(1);

}

if ((in=fopen(argv[1],"r"))==NULL)

{

printf("Can not open %s\n",argv[1]);

}

row=0;

while (fgets(line,81,in)!=NULL)

{

printf(" %3d: %s", ++row, line);

}

fclose(in);

return 0;

}

(2)改造上面的程式，若指令行中給出多個檔案名，逐個加行号顯示檔案内容

[參考解答]

#include

#include

int main(int argc,char *argv[])

{

FILE *in;

char line[81];

int row;

if (argc<2) //對于指令行中參數個數有要求的程式，常用argc檢查參數是否夠用

{

printf("Usage: %s textfile \n",argv[0]);

exit(1);

}

int n;

for (n=1; n

{

printf("%s:\n", argv[n]);

in=fopen(argv[n],"r");

if (in==NULL)

{

printf("Can not open\n\n");

}

else

{

row=0;

while (fgets(line,81,in)!=NULL)

{

printf(" %3d: %s", ++row, line);

}

printf("\n\n");

}

fclose(in);

}

return 0;

}