new lseek

forkrun.bash

@@ -1614,12 +1614,12 @@ forkrun_lseek_setup() {
     case "${USER}" in
         root)
             mkdir -p /usr/local/lib/bash
-            curl -o /usr/local/lib/bash/lseek 'https://github.com/jkool702/forkrun/raw/main/lseek'
+            curl -o /usr/local/lib/bash/lseek 'https://github.com/jkool702/forkrun/raw/main/lseek_builtin/lseek'
         ;;
         *)
             mkdir -p /dev/shm/.forkrun.lseek
             export BASH_LOADABLES_PATH=/dev/shm/.forkrun.lseek:${BASH_LOADABLES_PATH}
-            curl -o /dev/shm/.forkrun.lseek/lseek 'https://github.com/jkool702/forkrun/raw/main/lseek'
+            curl -o /dev/shm/.forkrun.lseek/lseek 'https://github.com/jkool702/forkrun/raw/main/lseek_builtin/lseek'
         ;;
     esac
 

lseek_builtin/lseek.c

@@ -0,0 +1,104 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <grp.h>
+#include <sys/types.h>
+#include "command.h"
+#include "builtins.h"
+#include "shell.h"
+#include "common.h"
+#include "bashgetopt.h"
+
+
+#ifdef USING_BASH_MALLOC
+#include <malloc/shmalloc.h>
+#endif
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifdef MAJOR_IN_MKDEV
+#  include <sys/mkdev.h>
+#endif
+
+#ifdef MAJOR_IN_SYSMACROS
+#  include <sys/sysmacros.h>
+#endif
+
+#ifndef errno
+extern int errno;
+#endif
+
+// Function declaration for our builtin
+static int lseek_main();
+int lseek_builtin();
+extern char **make_builtin_argv();
+
+// Metadata about the builtin
+static char *lseek_doc[] = {
+    "",
+    "----------------------------------------------",
+    "USAGE:    lseek <FD> <REL_OFFSET>",
+    "",
+    "Move the file descriptor <FD> by <REL_OFFSET>",
+    "bytes relative to its current byte offset.",
+    "",
+    "positive <REL_OFFSET> advances the <FD>",
+    "negative <REL_OFFSET> rewinds the <FD>",
+    "----------------------------------------------",
+    "",
+    NULL
+};
+
+// Struct to register the builtin with bash
+struct builtin lseek_struct = {
+    "lseek",              // Name of the builtin
+    lseek_builtin,        // Function to call
+    BUILTIN_ENABLED,      // Default status
+    lseek_doc,            // Documentation strings
+    "lseek <FD> <REL_OFFSET>",  // Array of long options
+    0                     // Number of long options
+};
+
+static int lseek_main(int argc, char **argv) {
+    if (argc != 3) {
+        fprintf(stderr, "\nIncorrect number of arguments.\nUSAGE: lseek <FD> <REL_OFFSET>\n");
+        return 1;
+    }
+
+    int fd = atoi(argv[1]);
+    if (fd == 0 && strcmp(argv[1], "0") != 0) {
+        fprintf(stderr,  "\nInvalid file descriptor.\n");
+        return 1;
+    }
+
+    off_t offset = atoll(argv[2]);
+    if (errno == ERANGE) {
+        fprintf(stderr, "\nOffset out of range.\n");
+        return 1;
+    }
+
+    if (lseek(fd, offset, SEEK_CUR) == (off_t) -1) {
+        fprintf(stderr, strerror(errno));
+        return 1;
+    }
+
+    return 0;
+}
+
+int lseek_builtin(WORD_LIST *list) {
+    int c, r;
+    char **v;
+    WORD_LIST *l;
+
+    v = make_builtin_argv(list, &c);
+    r = lseek_main(c, v);
+
+    return r;
+}
+

lseek_builtin/lseek_compile.sh

@@ -0,0 +1,20 @@
+git clone https://git.savannah.gnu.org/git/bash.git
+
+cd bash
+
+./configure
+
+make -j$(nproc)
+make -j$(nproc) all
+
+cd examples/loadables
+
+curl -o ./lseek.c 'https://github.com/jkool702/forkrun/raw/main/lseek_builtin/lseek.c'
+
+gcc -v -fPIC -DHAVE_CONFIG_H -DSHELL -DLOADABLE_BUILTIN -DSELECT_COMMAND -DUSING_BASH_MALLOC -g -O3 -Wno-parentheses -Wno-format-security -I. -I.. -I../.. -I../../lib -I../../builtins -I. -I../../include -I../../lib/malloc -I/mnt/ramdisk/bash -I/mnt/ramdisk/bash/lib -I/mnt/ramdisk/bash/builtins -L ../../lib/malloc -L ../.. -L /usr/lib/bash -I/usr/include/bash -I/usr/include/bash/builtins -I/usr/include/bash/include -c -o lseek.o lseek.c;
+gcc -v -DSELECT_COMMAND -DLOADABLE_BUILTIN -DHAVE_CONFIG_H -DSHELL -DUSING_BASH_MALLOC -shared -Wl,-soname,lseek -L ../../lib/malloc -L ../.. -L /usr/lib/bash -O3 -o lseek lseek.o; 
+
+mkdir -p /usr/local/lib/bash
+cp lseek /usr/local/lib/bash
+
+enable lseek