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add stdin redirection and refactor

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This commit is contained in:
Chris Cromer 2021-07-22 22:16:00 -04:00
parent 5f9b4bf81d
commit 83c0aa17b1
3 changed files with 43 additions and 27 deletions
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4
src/include/redirect.h
View File

@ -12,8 +12,6 @@
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdbool.h>
#ifndef _MYSHELLIN_REDIRECT
#define _MYSHELLIN_REDIRECT
@ -45,7 +43,7 @@ typedef struct {
/**
* Whether or not to truncate or append the file.
*/
bool append;
int flags;
} Redirect;
/**

59
src/loop.c
View File

@ -13,6 +13,7 @@
*/
#define _GNU_SOURCE
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@ -65,43 +66,63 @@ void loop() {
StringArray *args = create_string_array();
enum FileType {FileType_none, FileType_stdout, FileType_stderr};
enum FileType get_file_name = FileType_none;
Redirect out = {.fd = 1, .fd_new = -1, .fd_copy = -1, .filename = NULL, .append = false};
Redirect err = {.fd = 2, .fd_new = -1, .fd_copy = -1, .filename = NULL, .append = false};
int get_file_name = -1;
Redirect in = {.fd = STDIN_FILENO, .fd_new = -1, .fd_copy = -1, .filename = NULL, .flags = O_RDONLY};
Redirect out = {.fd = STDOUT_FILENO, .fd_new = -1, .fd_copy = -1, .filename = NULL, .flags = O_WRONLY | O_CREAT | O_TRUNC};
Redirect err = {.fd = STDERR_FILENO, .fd_new = -1, .fd_copy = -1, .filename = NULL, .flags = O_WRONLY | O_CREAT | O_TRUNC};
char *saveptr = NULL;
char *token = strtok_r(line, " ", &saveptr);
while (token) {
if (get_file_name == FileType_stdout) {
if (get_file_name == STDIN_FILENO) {
// get file name for stdin redirect
set_filename(&in, token);
get_file_name = -1;
}
else if (get_file_name == STDOUT_FILENO) {
// get file name for stdout redirect
set_filename(&out, token);
get_file_name = FileType_none;
get_file_name = -1;
}
else if (get_file_name == 2) {
else if (get_file_name == STDERR_FILENO) {
// get file name for stderr redirect
set_filename(&err, token);
get_file_name = FileType_none;
get_file_name = -1;
}
else if (strcmp(token, ">") == 0 || strcmp(token, "1>") == 0) {
// redirect stdout and overwrite
get_file_name = FileType_stdout;
out.append = false;
get_file_name = STDOUT_FILENO;
if ((out.flags & O_APPEND) == O_APPEND) {
out.flags &= ~O_APPEND;
out.flags |= O_TRUNC;
}
}
else if (strcmp(token, ">>") == 0 || strcmp(token, "1>>") == 0) {
// redirect stdout and append
get_file_name = FileType_stdout;
out.append = true;
get_file_name = STDOUT_FILENO;
if ((out.flags & O_TRUNC) == O_TRUNC) {
out.flags &= ~O_TRUNC;
out.flags |= O_APPEND;
}
}
else if (strcmp(token, "2>") == 0) {
// redirect stdout and overwrite
get_file_name = FileType_stderr;
err.append = false;
// redirect stderr and overwrite
get_file_name = STDERR_FILENO;
if ((err.flags & O_APPEND) == O_APPEND) {
err.flags &= ~O_APPEND;
err.flags |= O_TRUNC;
}
}
else if (strcmp(token, "2>>") == 0) {
// redirect stdout and append
get_file_name = FileType_stderr;
err.append = true;
// redirect stderr and append
get_file_name = STDERR_FILENO;
if ((err.flags & O_TRUNC) == O_TRUNC) {
err.flags &= ~O_TRUNC;
err.flags |= O_APPEND;
}
}
else if (strcmp(token, "<") == 0) {
get_file_name = STDIN_FILENO;
}
else {
insert_string_array(args, token);
@ -121,6 +142,7 @@ void loop() {
open_redirect(&err);
open_redirect(&out);
open_redirect(&in);
if (is_builtin(args->array[0])) {
run_builtin(args);
@ -129,6 +151,7 @@ void loop() {
launch_program(args);
}
close_redirect(&in);
close_redirect(&out);
close_redirect(&err);

7
src/redirect.c
View File

@ -27,12 +27,7 @@ void open_redirect(Redirect *redirect) {
perror("dup");
}
else {
if (redirect->append) {
redirect->fd_new = open(redirect->filename, O_WRONLY | O_CREAT | O_APPEND, 0664);
}
else {
redirect->fd_new = open(redirect->filename, O_WRONLY | O_CREAT | O_TRUNC, 0664);
}
redirect->fd_new = open(redirect->filename, redirect->flags, 0664);
if (redirect->fd_new == -1) {
fprintf(stderr, "open: Could not open file %s: \"%s\"\n", redirect->filename, strerror(errno));
free(redirect->filename);