c - Code doesn't work, getting error: segmentation fault(core dumped) -
can explain why snippet of code doesn't work? intended duplicate file, when compile segmentation fault(core dumped), appreciate critics. sorry if there typos.
#include <stdio.h> #include <stdlib.h> #define bufsize 256 #define maxlen 30 void copy(file *source,file *dest); int main(void) { file *fs, *fa; // fs source file, fa copy char file_src[maxlen]; // name of source file char file_app[maxlen]; // name of copy file puts("file copy program\n\n"); puts("enter name of source file:"); gets(file_src); // file name if(fs=fopen(file_src,"r")==null) // error checking { fprintf(stderr,"cant open %s.\n",file_src); exit(exit_failure); } if(setvbuf(fs,null,_iofbf,bufsize)!=0) // set buffer fs { fprintf(stderr,"cant create input buffer.\n"); exit(exit_failure); } puts("now enter copy name file:"); gets(file_app); // file name if(fa=fopen(file_app,"w")==null) // error checking { fprintf(stderr,"cant open %s.\n",file_app); exit(exit_failure); } if(setvbuf(fa,null,_iofbf,bufsize)!=0) // set buffer fa { fprintf(stderr,"cant create output buffer.\n"); exit(exit_failure); } copy(fs,fa); // copy file fs fa if(ferror(fs)!=0) { fprintf(stderr,"error in reading file\n"); exit(exit_failure); } if(ferror(fa)!=0) { fprintf(stderr,"error in writing file\n"); exit(exit_failure); } puts("done"); return 0; } void copy(file *source,file *dest) { size_t bytes=0; static char temp[bufsize]; while(bytes=fread(temp,sizeof(char),bufsize,source) > 0) fwrite(temp,sizeof(char),bytes,dest); }
this:
if(fs=fopen(file_src,"r")==null) is wrong. ending assigning fs null, when open succeeds, not checked , causes fault when null used in later calls.
it must be
if((fs = fopen(file_src, "r")) == null) due how operator priority works in c.
by way, generic copying program should open files in binary mode.
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