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user: fix stdio stream pos; remove the shell pipe redir workaround

This commit is contained in:
dzwdz 2023-09-07 01:31:09 +02:00
parent 9c3ee3807c
commit 58eed4a579
2 changed files with 4 additions and 26 deletions
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26
src/cmd/shell/shell.c
View File

@ -101,30 +101,8 @@ void run_args(int argc, char **argv, struct redir *redir) {
if (!f) {
err(1, "couldn't open %s for redirection", redir->stdout);
}
/* a workaround for file offsets not being preserved across exec()s.
* TODO document that weird behaviour of exec() */
hid_t p[2];
if (_sys_pipe(p, 0) < 0) {
errx(1, "couldn't create redirection pipe");
}
if (!_sys_fork(FORK_NOREAP, NULL)) {
/* the child forwards data from the pipe to the file */
const size_t buflen = 512;
char *buf = malloc(buflen);
if (!buf) err(1, "when redirecting");
close(p[1]);
for (;;) {
long len = _sys_read(p[0], buf, buflen, 0);
if (len <= 0) exit(0);
fwrite(buf, 1, len, f);
if (ferror(f)) exit(0);
}
}
fclose(f);
close(p[0]);
if (_sys_dup(p[1], 1, 0) < 0) {
// TODO fileno error checking
if (_sys_dup(fileno(f), 1, 0) < 0) {
errx(1, "dup() failed when redirecting");
}
}

4
src/libc/stdio/file.c
View File

@ -10,8 +10,8 @@
#include <unistd.h>
static FILE _stdin_null = { .fd = STDIN_FILENO };
static FILE _stdout_null = { .fd = STDOUT_FILENO };
static FILE _stderr_null = { .fd = STDERR_FILENO };
static FILE _stdout_null = { .fd = STDOUT_FILENO, .pos = -1 };
static FILE _stderr_null = { .fd = STDERR_FILENO, .pos = -1 };
FILE *const stdin = &_stdin_null;
FILE *const stdout = &_stdout_null;
FILE *const stderr = &_stderr_null;