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#How to use the "fread" function in C language?
The usage of the "fread" function in C language is "size_tf read(void *buffer,size_t size,size_t count,FILE *stream)". Its function is to read data from a file stream. Take count elements, each element is size bytes.
Example 1
#include <stdio.h> #include <process.h> #include <string.h> int main() { FILE *stream; char msg[]="this is a test"; char buf[20]; if ((stream=fopen("dummy.fil","w+"))==NULL) { fprintf(stderr,"cannot open output file.\n"); return 1; } /*write some data to the file*/ fwrite(msg,1,strlen(msg)+1,stream); /*seek to the beginning of the file*/ fseek(stream,0,SEEK_SET); /*read the data and display it*/ fread(buf,1,strlen(msg)+1,stream); printf("%s\n",buf); fclose(stream); system("pause"); return 0; }
Example 2
int main(void) { FILE *stream; char list[30]; int i,numread,numwritten; /*open file in text mode:*/ if ((stream=fopen("fread.out","w+t"))!=NULL) { for (i=0;i<25;i++) { list[i]=(char)('z'-i); } /*write 25 characters to stram*/ numwritten=fwrite(list,sizeof(char),25,stream); printf("Wrote %d items\n",numwritten); fclose(stream); } else printf("Problem opening the file\n"); if ((stream=fopen("fread.out","r+t"))!=NULL) { numread=fread(list,sizeof(char),25,stream); printf("Number of items read =%d\n",numread); printf("Contents of buffer=%.25s\n",list); fclose(stream); } else { printf("File could not be opened\n"); } system("pause"); return 0; }
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