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Code Issues 1 Releases Wiki Activity

Add fseek.

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This commit is contained in:
Calvin Rose 2018-02-04 12:58:40 -05:00
parent 4b89789f69
commit 4971ef58d2
1 changed files with 41 additions and 6 deletions
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47
src/core/io.c
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@ -49,10 +49,6 @@ DstAbstractType dst_io_filetype = {
static int checkflags(const uint8_t *str, int32_t len) {
int flags = 0;
int32_t i;
if (len && str[0] == ':') {
len--;
str++;
}
if (!len || len > 3) return -1;
switch (*str) {
default:
@ -149,13 +145,19 @@ static int dst_io_fopen(DstArgs args) {
if (!dst_checktype(args.v[0], DST_STRING)) return dst_throw(args, "expected string filename");
fname = dst_unwrap_string(args.v[0]);
if (args.n == 2) {
if (!dst_checktype(args.v[1], DST_STRING)) return dst_throw(args, "expected string mode");
if (!dst_checktype(args.v[1], DST_STRING) &&
!dst_checktype(args.v[1], DST_SYMBOL))
return dst_throw(args, "expected string mode");
fmode = dst_unwrap_string(args.v[1]);
modelen = dst_string_length(fmode);
} else {
fmode = (const uint8_t *)"r";
modelen = 1;
}
if (fmode[0] == ':') {
fmode++;
modelen--;
}
if ((flags = checkflags(fmode, modelen)) < 0) return dst_throw(args, "invalid file mode");
f = fopen((const char *)fname, (const char *)fmode);
if (!f) return dst_throw(args, "could not open file");
@ -249,12 +251,44 @@ static int dst_io_gc(void *p, size_t len) {
static int dst_io_fclose(DstArgs args) {
IOFile *iof = checkfile(args, 0);
if (!iof) return 1;
if (iof->flags & (IO_CLOSED | IO_NOT_CLOSEABLE)) return dst_throw(args, "could not close file");
if (iof->flags & (IO_CLOSED | IO_NOT_CLOSEABLE))
return dst_throw(args, "could not close file");
if (fclose(iof->file)) return dst_throw(args, "could not close file");
iof->flags |= IO_CLOSED;
return dst_return(args, dst_wrap_abstract(iof));
}
/* Seek a file */
static int dst_io_fseek(DstArgs args) {
long int offset = 0;
int whence = SEEK_CUR;
IOFile *iof = checkfile(args, 0);
if (!iof) return 1;
if (args.n >= 2) {
const uint8_t *whence_sym;
if (!dst_checktype(args.v[1], DST_SYMBOL))
return dst_throw(args, "expected symbol");
whence_sym = dst_unwrap_symbol(args.v[1]);
if (!dst_cstrcmp(whence_sym, ":cur")) {
whence = SEEK_CUR;
} else if (!dst_cstrcmp(whence_sym, ":set")) {
whence = SEEK_SET;
} else if (!dst_cstrcmp(whence_sym, ":end")) {
whence = SEEK_END;
} else {
return dst_throw(args, "expected one of :cur, :set, :end");
}
if (args.n >= 3) {
if (!dst_checktype(args.v[2], DST_INTEGER))
return dst_throw(args, "expected integer");
offset = dst_unwrap_integer(args.v[2]);
}
}
if (fseek(iof->file, offset, whence))
return dst_throw(args, "error seeking file");
return dst_return(args, args.v[0]);
}
/* Define the entry point of the library */
#ifdef DST_LIB
#define dst_lib_io _dst_init
@ -266,6 +300,7 @@ static const DstReg cfuns[] = {
{"file-read", dst_io_fread},
{"file-write", dst_io_fwrite},
{"file-flush", dst_io_fflush},
{"file-seek", dst_io_fseek},
{NULL, NULL}
};