diff options
| -rw-r--r-- | src/stdio/fmemopen.c | 51 |
1 files changed, 48 insertions, 3 deletions
diff --git a/src/stdio/fmemopen.c b/src/stdio/fmemopen.c index 77a60746..cc72a420 100644 --- a/src/stdio/fmemopen.c +++ b/src/stdio/fmemopen.c @@ -3,14 +3,59 @@ static ssize_t mread(FILE *f, unsigned char *buf, size_t len) { - memcpy(buf, + size_t rem = f->memsize - f->mempos; + if (len > rem) len = rem; + memcpy(buf, f->membuf+f->mempos, len); + f->mempos += len; + return len; +} + +static ssize_t mwrite(FILE *f, const unsigned char *buf, size_t len) +{ + size_t rem; + if (f->memmode == 'a') f->mempos = f->memsize; + rem = f->memlim - f->mempos; + if (len > rem) len = rem; + memcpy(f->membuf+f->mempos, buf, len); + f->mempos += len; + if (f->mempos >= f->memsize) { + f->memsize = f->mempos; + } + return len; } FILE *fmemopen(void *buf, size_t size, const char *mode) { - FILE *f = calloc(sizeof(FILE), 1); + FILE *f; + int plus = !!strchr(mode, '+'); + + if (!size || !strchr("rwa", *mode)) { + errno = EINVAL; + return 0; + } + + if (!buf && size > SIZE_MAX-sizeof(FILE)-BUFSIZ-UNGET) { + errno = ENOMEM; + return 0; + } + + f = calloc(sizeof(FILE) + UNGET + BUFSIZ + (buf?0:size), 1); if (!f) return 0; + f->fd = -1; + f->lbf = EOF; + f->buf = (unsigned char *)(f+1) + UNGET; + f->buf_size = BUFSIZ; + if (!buf) buf = f->buf + BUFSIZ; - // + if (!plus) f->flags = (*mode == 'r') ? F_NOWR : F_NORD; + if (*mode == 'a') f->mempos = strchr(buf, 0)-buf; + + f->read = mread; + f->write = mwrite; + f->seek = mseek; + f->flush = mflush; + f->close = mclose; + + return f; } #endif |