I’m stuck on Stage #(Redirect stdout #jv1) of the build your shell project. I am using C. My github repo:
Here are my logs:
[tester::#JV1] Running tests for Stage #JV1 (Redirection - Redirect stdout)
[tester::#JV1] [setup] export PATH=/tmp/banana/pineapple/banana:$PATH
[tester::#JV1] Running ./your_program.sh
[tester::#JV1] [setup] echo -n "orange" > "/tmp/bar/orange"
[tester::#JV1] [setup] echo -n "pineapple" > "/tmp/bar/pineapple"
[tester::#JV1] [setup] echo -n "strawberry" > "/tmp/bar/strawberry"
[your-program] $ ls -1 /tmp/bar > /tmp/foo/foo.md
[your-program] $ cat /tmp/foo/foo.md
[your-program] orange
[your-program] pineapple
[your-program] strawberry
[tester::#JV1] ✓ Received redirected file content
[your-program] $ echo 'Hello James' 1> /tmp/foo/qux.md
[tester::#JV1] Expected prompt ("$ ") but received ""
[tester::#JV1] Assertion failed.
[tester::#JV1] Test failed
And here’s my code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <ctype.h>
#include <fcntl.h>
#define CMD_LST_SIZE 5
#define MAX_ARGS 50
char *cmd_lst[] = {"echo", "exit", "type", "pwd", "cd"};
// Check if input command matches a known command
int is_cmd(char *cmd) {
for (int i = 0; i < CMD_LST_SIZE; i++) {
if (strcmp(cmd, cmd_lst[i]) == 0) {
return i;
}
}
return -1;
}
// Parse input line into arguments, handling quotes and escape characters
int parse_input(char *input, char *args[], int max_args) {
int argc = 0;
char *p = input;
while (*p && argc < max_args - 1) {
while (isspace((unsigned char)*p)) p++;
if (*p == '\0') break;
char buffer[1024] = {0};
int buf_idx = 0;
while (*p && !isspace((unsigned char)*p)) {
if (*p == '\'') {
p++;
while (*p && *p != '\'') buffer[buf_idx++] = *p++;
if (*p == '\'') p++;
else {
fprintf(stderr, "parse_input: missing closing single quote\n");
return -1;
}
} else if (*p == '"') {
p++;
while (*p && *p != '"') buffer[buf_idx++] = *p++;
if (*p == '"') p++;
else {
fprintf(stderr, "parse_input: missing closing double quote\n");
return -1;
}
} else {
buffer[buf_idx++] = *p++;
}
}
args[argc] = malloc(buf_idx + 1);
if (!args[argc]) {
fprintf(stderr, "parse_input: memory allocation failed\n");
return -1;
}
memcpy(args[argc], buffer, buf_idx);
args[argc][buf_idx] = '\0';
argc++;
}
args[argc] = NULL;
return argc;
}
// Free dynamically allocated arguments
void free_args(char *args[], int argc) {
for (int i = 0; i < argc; i++) {
free(args[i]);
}
}
int main() {
char input[1024];
setbuf(stdout, NULL); // Flush stdout after each printf
while (1) {
fputs("$ ", stdout);
fflush(stdout);
if (fgets(input, sizeof(input), stdin) == NULL) break;
char *args[MAX_ARGS];
int arg_count = parse_input(input, args, MAX_ARGS);
if (arg_count <= 0) {
free_args(args, arg_count);
continue;
}
char *outfile = NULL;
int outfd = -1;
bool is_redirect = false;
// Detect output redirection
for (int i = 0; i < arg_count - 1; i++) {
if ((strcmp(args[i], ">") == 0 || strcmp(args[i], "1>") == 0) && args[i + 1]) {
outfile = args[i + 1];
// Remove redirection tokens from args[]
for (int j = i; j + 2 <= arg_count; j++) {
args[j] = args[j + 2];
}
arg_count -= 2;
is_redirect = true;
break;
}
}
int cmd_type = is_cmd(args[0]);
switch (cmd_type) {
case 0: // echo
if (is_redirect) {
outfd = open(outfile, O_CREAT | O_WRONLY | O_TRUNC, 0644);
if (outfd < 0) {
fprintf(stderr, "Error opening file %s: %s\n", outfile, strerror(errno));
free_args(args, arg_count);
continue;
}
dup2(outfd, STDOUT_FILENO);
close(outfd);
}
for (int i = 1; i < arg_count; i++) {
printf("%s", args[i]);
if (i < arg_count - 1) printf(" ");
}
printf("\n");
break;
case 1: // exit
{
int status = 0;
if (arg_count > 1) status = atoi(args[1]);
free_args(args, arg_count);
return status;
}
case 2: // type
if (arg_count < 2) {
fprintf(stdout, "type: missing argument\n");
} else {
int builtin = is_cmd(args[1]);
if (builtin >= 0) {
fprintf(stdout, "%s is a shell builtin\n", args[1]);
} else {
char *path = getenv("PATH");
if (path) {
char *path_dup = strdup(path);
char *dir = strtok(path_dup, ":");
bool found = false;
while (dir != NULL) {
char full_path[512];
snprintf(full_path, sizeof(full_path), "%s/%s", dir, args[1]);
if (access(full_path, X_OK) == 0) {
fprintf(stdout, "%s is %s\n", args[1], full_path);
found = true;
break;
}
dir = strtok(NULL, ":");
}
if (!found) {
fprintf(stdout, "%s: not found\n", args[1]);
}
free(path_dup);
}
}
}
break;
case 3: // pwd
{
char cwd[512];
if (getcwd(cwd, sizeof(cwd)) != NULL) {
printf("%s\n", cwd);
} else {
perror("pwd");
}
break;
}
case 4: // cd
{
char *target = arg_count >= 2 ? args[1] : getenv("HOME");
if (!target) {
fprintf(stderr, "cd: HOME not set\n");
break;
}
if (chdir(target) != 0) {
fprintf(stderr, "cd: %s: %s\n", target, strerror(errno));
}
break;
}
default: // external command
{
pid_t pid = fork();
if (pid == 0) {
if (is_redirect) {
outfd = open(outfile, O_CREAT | O_WRONLY | O_TRUNC, 0644);
if (outfd < 0) {
fprintf(stderr, "Error opening file %s: %s\n", outfile, strerror(errno));
exit(1);
}
dup2(outfd, STDOUT_FILENO);
close(outfd);
}
execvp(args[0], args);
fprintf(stderr, "%s: command not found\n", args[0]);
exit(127);
} else if (pid > 0) {
int status;
waitpid(pid, &status, 0);
} else {
perror("fork failed");
}
break;
}
}
free_args(args, arg_count);
}
return 0;
}
