3 files changed, 153 insertions, 0 deletions
diff --git a/42sh/src/IO/IOBackend.h b/42sh/src/IO/IOBackend.h
new file mode 100644
index 0000000..dc190db
--- /dev/null
+++ b/42sh/src/IO/IOBackend.h
@@ -0,0 +1,27 @@
+#ifndef IOBACKEND_H
+#define IOBACKEND_H
+
+#include "utils/libstring.h"
+
+#undef DEFAULT_RW_SIZE
+
+/**
+ * @brief Represents the 'count' parameter used in read/write syscalls.
+ */
+#define DEFAULT_RW_SIZE 256
+
+/**
+ * @brief Retrieves the input provided to the main program.
+ *
+ * This function processes the program arguments and returns them as a single
+ * heap-allocated string. The returned string always ends with a null byte
+ * (`\0`).
+ *
+ * @param argc The argument count passed to main().
+ * @param argv The argument vector passed to main().
+ * @return A pointer to a `struct string` containing the input, or `NULL` on
+ * failure.
+ */
+struct string *get_input(int argc, char *argv[]);
+
+#endif /* ! IOBACKEND_H */
diff --git a/42sh/src/IO/Makefile.am b/42sh/src/IO/Makefile.am
new file mode 100644
index 0000000..27b5721
--- /dev/null
+++ b/42sh/src/IO/Makefile.am
@@ -0,0 +1,11 @@
+lib_LIBRARIES = libIO.a
+
+libIO_a_SOURCES =  \
+  IOBackend.h \
+  string_input.c
+
+libIO_a_CPPFLAGS = -I$(top_srcdir)/src
+
+libIO_a_CFLAGS = -std=c99 -Werror -Wall -Wextra -Wvla -pedantic
+
+noinst_LIBRARIES = libIO.a
diff --git a/42sh/src/IO/string_input.c b/42sh/src/IO/string_input.c
new file mode 100644
index 0000000..2f252fb
--- /dev/null
+++ b/42sh/src/IO/string_input.c
@@ -0,0 +1,115 @@
+#define _POSIX_C_SOURCE 200809L
+
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "IO/IOBackend.h"
+#include "utils/env.h"
+
+static void _usage_xerror(void)
+{
+    errx(2, "Usage:\n\
+    \t./42sh [--pretty-print] [FILENAME]\n\
+    \t./42sh [-c | --pretty-print] [FILENAME]\n\
+    \t./42sh [--pretty-print] [ < FILENAME ]");
+}
+
+static struct string *_parse_input(FILE *f)
+{
+    ssize_t r = 0;
+    struct string *output = string_create(NULL);
+    char buf[DEFAULT_RW_SIZE + 1] = { 0 };
+    do
+    {
+        r = fread(buf, sizeof(char), DEFAULT_RW_SIZE, f);
+        if (r == -1)
+        {
+            fprintf(stderr, "_parse_input: fread failed!");
+            return NULL;
+        }
+        buf[r] = 0;
+        string_pushstr(output, buf);
+    } while (r >= DEFAULT_RW_SIZE);
+
+    return output;
+}
+
+static void _add_newline(struct string *s)
+{
+    if (s->data[s->length - 1] != '\n')
+    {
+        string_pushc(s, '\n');
+    }
+}
+
+struct string *get_input(int argc, char *argv[])
+{
+    int i = 1;
+    bool s_input = false;
+    FILE *f = NULL;
+    while (i < argc && argv[i][0] == '-')
+    {
+        if (strcmp(argv[i], "-c") == 0)
+        {
+            s_input = true;
+            i++;
+            continue;
+        }
+
+        if (strcmp(argv[i], "--pretty-print") == 0)
+        {
+            env_set("PRETTY_PRINT", "TRUE");
+            i++;
+            continue;
+        }
+
+        _usage_xerror();
+    }
+    if (i == argc)
+    {
+        f = stdin;
+    }
+    else
+    {
+        char *input = argv[i];
+        if (s_input)
+        {
+            f = fmemopen(input, strlen(input) + 1, "r");
+        }
+        else
+        {
+            f = fopen(input, "r");
+            env_set("0", input);
+        }
+    }
+
+    if (!f)
+    {
+        errx(2, "Invalid path!");
+    }
+
+    struct string *string_input = _parse_input(f);
+    if (f != stdin)
+    {
+        fclose(f);
+    }
+
+    int nb_args = 0;
+    i++;
+    for (; i < argc; i++)
+    {
+        nb_args++;
+        char buf[16] = { 0 };
+        sprintf(buf, "%d", nb_args);
+        env_set(buf, argv[i]);
+    }
+
+    char buf2[16] = { 0 };
+    sprintf(buf2, "%d", (s_input && nb_args > 0) ? 1 : nb_args);
+    env_set("#", buf2);
+
+    _add_newline(string_input);
+    return string_input;
+}