diff options
Diffstat (limited to '8.2/stdio.c')
-rw-r--r-- | 8.2/stdio.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/8.2/stdio.c b/8.2/stdio.c new file mode 100644 index 0000000..dd6cbef --- /dev/null +++ b/8.2/stdio.c @@ -0,0 +1,86 @@ +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#include <stdlib.h> +#include "stdio.h" + +#define PERMS 0666 + +FILE _iob[OPN_MAX] = { + {0, (char *) NULL, (char *) NULL, {1, 0, 0, 1, 0, 0}, 0}, + {0, (char *) NULL, (char *) NULL, {0, 1, 0, 1, 0, 0}, 1}, + {0, (char *) NULL, (char *) NULL, {0, 1, 1, 0, 0, 0}, 2}, +}; + +FILE *fopen(char *name, char *mode) +{ + int fd; + FILE *fp; + + if (*mode != 'r' && *mode != 'w' && *mode != 'a') + return NULL; + + for (fp = _iob; fp < _iob + OPN_MAX; ++fp) + if (fp->flag.is_read == 0 && fp->flag.is_write == 0) + break; + if (fp == _iob + OPN_MAX) + return NULL; + + if (*mode == 'w') { + fd = creat(name, PERMS); + } else if (*mode == 'a') { + if ((fd = open(name, O_WRONLY)) == -1) + fd = creat(name, PERMS); + lseek(fd, 0L, 2); + } else { + fd = open(name, O_RDONLY); + } + + if (fd == -1) + return NULL; + + fp->fd = fd; + fp->cnt = 0; + fp->base = NULL; + fp->flag.is_unbuf = 0; + fp->flag.is_buf = 1; + fp->flag.is_eof = 0; + fp->flag.is_err = 0; + if (*mode == 'r') { + fp->flag.is_read = 1; + fp->flag.is_write = 0; + } else { + fp->flag.is_write = 1; + fp->flag.is_read = 0; + } + + return fp; +} + +int _fillbuf(FILE *fp) +{ + int bufsize; + + if (fp->flag.is_read == 0 || + fp->flag.is_err == 1 || + fp->flag.is_eof == 1) + return EOF; + + bufsize = (fp->flag.is_unbuf == 1) ? 1 : BUFSIZ; + if (fp->base == NULL) + if ((fp->base = (char *) malloc(bufsize)) == NULL) + return EOF; + fp->ptr = fp->base; + + fp->cnt = read(fp->fd, fp->base, bufsize); + if (--fp->cnt < 0) { + if (fp->cnt == -1) + fp->flag.is_eof = 1; + else + fp->flag.is_err = 1; + fp->cnt = 0; + return EOF; + } + + return (unsigned char) *fp->ptr++; +} |