pr: Add ps && hexdump (#26)

* Adding hexdump and ps.c

* Add hexdump and ps command descriptions to help

* Update with missing ;

src/userland/cli/help.c

@@ -25,6 +25,8 @@ int main(int argc, char **argv) {
     printf("date           - Print current date and time\n");
     printf("uptime         - Print system uptime\n");
     printf("meminfo        - Print memory information\n");
+    printf("hexdump <file> - Display file contents in hexadecimal.\n");
+    printf("ps [options]   - List running processes\n");
     printf("lsblk          - List block devices and partitions\n");
     printf("cowsay [msg]   - Fun cow says something\n");
     printf("beep           - Make a beep sound\n");

src/userland/cli/hexdump.c

@@ -0,0 +1,111 @@
+// Copyright (c) 2023-2026 Chris (boreddevnl)
+// This software is released under the GNU General Public License v3.0. See LICENSE file for details.
+// This header needs to maintain in any file it is present in, as per the GPL license terms.
+// BOREDOS_APP_DESC: Display file contents in hexadecimal.
+
+#include "syscall.h"
+#include "stdlib.h"
+#include "string.h"
+#include "stdio.h"
+
+#define BYTES_PER_LINE 16
+
+static int sc_strcmp(const char *a, const char *b) {
+    while (*a && *a == *b) {
+        a++;
+        b++;
+    }
+
+    return (unsigned char)*a - (unsigned char)*b;
+}
+
+static void print_usage(void) {
+    printf("Usage: hexdump <file>\n");
+    printf("\n");
+    printf("Display file contents in hexadecimal.\n");
+}
+
+static void print_hex_byte(unsigned char b) {
+    const char *hex = "0123456789ABCDEF";
+
+    putchar(hex[(b >> 4) & 0xF]);
+    putchar(hex[b & 0xF]);
+}
+
+static void print_hex32(unsigned int v) {
+    const char *hex = "0123456789ABCDEF";
+
+    for (int i = 7; i >= 0; i--) {
+        putchar(hex[(v >> (i * 4)) & 0xF]);
+    }
+}
+
+int main(int argc, char **argv) {
+    int fd;
+    int offset = 0;
+
+    unsigned char buf[BYTES_PER_LINE];
+
+    if (argc < 2) {
+        print_usage();
+        return 1;
+    }
+
+    if (sc_strcmp(argv[1], "-h") == 0 ||
+        sc_strcmp(argv[1], "--help") == 0) {
+        print_usage();
+        return 0;
+    }
+
+    fd = sys_open(argv[1], "r");
+
+    if (fd < 0) {
+        printf("hexdump: cannot open '%s'\n", argv[1]);
+        return 1;
+    }
+
+    while (1) {
+        int bytes = sys_read(fd, buf, BYTES_PER_LINE);
+
+        if (bytes <= 0)
+            break;
+
+        // Offset
+        print_hex32(offset);
+        printf("  ");
+
+        // Hex bytes
+        for (int i = 0; i < BYTES_PER_LINE; i++) {
+            if (i < bytes) {
+                print_hex_byte(buf[i]);
+            } else {
+                printf("  ");
+            }
+
+            printf(" ");
+
+            if (i == 7)
+                printf(" ");
+        }
+
+        printf(" |");
+
+        // ASCII preview
+        for (int i = 0; i < bytes; i++) {
+            unsigned char c = buf[i];
+
+            if (c >= 32 && c <= 126)
+                putchar(c);
+            else
+                putchar('.');
+        }
+
+        printf("|\n");
+
+        offset += bytes;
+    }
+
+    sys_close(fd);
+
+    return 0;
+}

src/userland/cli/ps.c

@@ -0,0 +1,299 @@
+// Copyright (c) 2023-2026 Chris (boreddevnl)
+// This software is released under the GNU General Public License v3.0. See LICENSE file for details.
+// This header needs to maintain in any file it is present in, as per the GPL license terms.
+// BOREDOS_APP_DESC: List running processes.
+
+#include "../libc/syscall.h"
+#include "../libc/stdlib.h"
+#include "../libc/string.h"
+#include "../libc/stdio.h"
+
+#define MAX_PROC_ENTRIES 64
+
+static int sc_strcmp(const char *a, const char *b) {
+    while (*a && *a == *b) {
+        a++;
+        b++;
+    }
+    return (unsigned char)*a - (unsigned char)*b;
+}
+
+static int is_numeric(const char *s) {
+    int i = 0;
+
+    if (!s || !s[0])
+        return 0;
+
+    while (s[i]) {
+        if (s[i] < '0' || s[i] > '9')
+            return 0;
+        i++;
+    }
+
+    return 1;
+}
+
+static void print_spaces(int count) {
+    for (int i = 0; i < count; i++)
+        printf(" ");
+}
+
+static void print_padded(const char *s, int width) {
+    int len;
+
+    if (!s)
+        s = "";
+
+    printf("%s", s);
+
+    len = (int)strlen(s);
+
+    if (len < width)
+        print_spaces(width - len);
+    else
+        printf(" ");
+}
+
+static int find_value(const char *buf, const char *key) {
+    char *p = (char*)buf;
+    int key_len = strlen(key);
+
+    while (*p) {
+        if (memcmp(p, key, key_len) == 0 && p[key_len] == ':') {
+            p += key_len + 1;
+
+            while (*p == ' ' || *p == '\t')
+                p++;
+
+            return atoi(p);
+        }
+
+        while (*p && *p != '\n')
+            p++;
+
+        if (*p == '\n')
+            p++;
+    }
+
+    return 0;
+}
+
+static void find_string(const char *buf,
+                        const char *key,
+                        char *out,
+                        int max_len) {
+    char *p = (char*)buf;
+    int key_len = strlen(key);
+
+    out[0] = 0;
+
+    while (*p) {
+        if (memcmp(p, key, key_len) == 0 && p[key_len] == ':') {
+            int i = 0;
+
+            p += key_len + 1;
+
+            while (*p == ' ' || *p == '\t')
+                p++;
+
+            while (*p &&
+                   *p != '\n' &&
+                   *p != '\r' &&
+                   i < max_len - 1) {
+                out[i++] = *p++;
+            }
+
+            out[i] = 0;
+            return;
+        }
+
+        while (*p && *p != '\n')
+            p++;
+
+        if (*p == '\n')
+            p++;
+    }
+}
+
+static int read_file_to_buf(const char *path,
+                            char *buf,
+                            int max_len) {
+    int fd;
+    int bytes;
+
+    fd = sys_open(path, "r");
+
+    if (fd < 0)
+        return -1;
+
+    bytes = sys_read(fd, buf, max_len - 1);
+
+    sys_close(fd);
+
+    if (bytes < 0)
+        return -1;
+
+    buf[bytes] = 0;
+
+    return bytes;
+}
+
+static void format_mem(int kb, char *out) {
+    char tmp[32];
+
+    if (kb < 1024) {
+        itoa(kb, tmp);
+
+        strcpy(out, tmp);
+        strcat(out, " KB");
+    } else {
+        int mb = kb / 1024;
+        int frac = ((kb % 1024) * 10) / 1024;
+
+        itoa(mb, tmp);
+
+        strcpy(out, tmp);
+        strcat(out, ".");
+
+        itoa(frac, tmp);
+        strcat(out, tmp);
+        strcat(out, " MiB");
+    }
+}
+
+static void print_usage(void) {
+    printf("Usage: ps [options]\n");
+    printf("\n");
+    printf("Options:\n");
+    printf("  -a       Show all processes\n");
+    printf("  -i       Include idle tasks\n");
+    printf("  -m       Show memory usage\n");
+    printf("  -t       Show scheduler ticks\n");
+    printf("  -p PID   Show only one process\n");
+    printf("  -h       Show this help\n");
+}
+
+static void print_header(int show_mem,
+                         int show_ticks,
+                         int show_idle) {
+    print_padded("PID", 8);
+    print_padded("NAME", 22);
+
+    if (show_mem)
+        print_padded("MEMORY", 14);
+
+    if (show_ticks)
+        print_padded("TICKS", 12);
+
+    if (show_idle)
+        print_padded("IDLE", 8);
+
+    printf("\n");
+}
+
+int main(int argc, char **argv) {
+    int show_mem = 0;
+    int show_ticks = 0;
+    int include_idle = 0;
+    int show_idle_col = 0;
+    int filter_pid = -1;
+
+    FAT32_FileInfo entries[MAX_PROC_ENTRIES];
+
+    for (int i = 1; i < argc; i++) {
+        if (sc_strcmp(argv[i], "-m") == 0) {
+            show_mem = 1;
+        } else if (sc_strcmp(argv[i], "-t") == 0) {
+            show_ticks = 1;
+        } else if (sc_strcmp(argv[i], "-a") == 0) {
+            include_idle = 1;
+            show_idle_col = 1;
+        } else if (sc_strcmp(argv[i], "-i") == 0) {
+            include_idle = 1;
+            show_idle_col = 1;
+        } else if (sc_strcmp(argv[i], "-p") == 0 && i + 1 < argc) {
+            filter_pid = atoi(argv[++i]);
+        } else if (sc_strcmp(argv[i], "-h") == 0) {
+            print_usage();
+            return 0;
+        } else {
+            print_usage();
+            return 1;
+        }
+    }
+
+    int count = sys_list("/proc", entries, MAX_PROC_ENTRIES);
+
+    if (count < 0) {
+        printf("ps: failed to read /proc\n");
+        return 1;
+    }
+
+    print_header(show_mem, show_ticks, show_idle_col);
+
+    for (int i = 0; i < count; i++) {
+        char path[96];
+        char buf[512];
+        char name[64];
+        char mem_str[32];
+        char tmp[32];
+
+        int pid;
+        int memory_kb;
+        int ticks;
+        int idle;
+
+        if (!entries[i].is_directory)
+            continue;
+
+        if (!is_numeric(entries[i].name))
+            continue;
+
+        pid = atoi(entries[i].name);
+
+        if (filter_pid >= 0 && pid != filter_pid)
+            continue;
+
+        strcpy(path, "/proc/");
+        strcat(path, entries[i].name);
+        strcat(path, "/status");
+
+        if (read_file_to_buf(path, buf, sizeof(buf)) <= 0)
+            continue;
+
+        find_string(buf, "Name", name, sizeof(name));
+
+        memory_kb = find_value(buf, "Memory");
+        ticks = find_value(buf, "Ticks");
+        idle = find_value(buf, "Idle");
+
+        if (idle && !include_idle)
+            continue;
+
+        itoa(pid, tmp);
+        print_padded(tmp, 8);
+
+        if (!name[0])
+            strcpy(name, "Unknown");
+
+        print_padded(name, 22);
+
+        if (show_mem) {
+            format_mem(memory_kb, mem_str);
+            print_padded(mem_str, 14);
+        }
+
+        if (show_ticks) {
+            itoa(ticks, tmp);
+            print_padded(tmp, 12);
+        }
+
+        if (show_idle_col) {
+            print_padded(idle ? "yes" : "no", 8);
+        }
+
+        printf("\n");
+    }
+
+    return 0;
+}