From 67161e1b7dda8f9ffe4a94e89b606dff31263768 Mon Sep 17 00:00:00 2001
From: luishernandez <lahr730@gmail.com>
Date: Tue, 11 Feb 2025 17:39:25 -0500
Subject: [PATCH] 3-shellp1
---
dshlib.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 93 insertions(+)
create mode 100644 dshlib.c
diff --git a/dshlib.c b/dshlib.c
new file mode 100644
index 0000000..3ee5c6c
--- /dev/null
+++ b/dshlib.c
@@ -0,0 +1,93 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "dshlib.h"
+
+/*
+ * trim: Removes leading and trailing whitespace from a string in-place.
+ * Returns a pointer to the first non-space character.
+ */
+static char *trim(char *str)
+{
+ /* Trim leading spaces */
+ while (isspace((unsigned char)*str))
+ str++;
+
+ if (*str == '\0') /* All spaces? */
+ return str;
+
+ /* Trim trailing spaces */
+ char *end = str + strlen(str) - 1;
+ while (end > str && isspace((unsigned char)*end)) {
+ *end = '\0';
+ end--;
+ }
+ return str;
+}
+
+/*
+ * build_cmd_list:
+ * - Splits the provided cmd_line into commands separated by '|'
+ * - For each command it trims leading/trailing spaces and then splits the
+ * command into tokens (using whitespace as the delimiter).
+ * - The first token is stored in the exe field (if it is not too long).
+ * - Any subsequent tokens are concatenated (with no intervening spaces)
+ * and stored in the args field.
+ *
+ * Returns:
+ * OK if the command was parsed successfully.
+ * ERR_TOO_MANY_COMMANDS if more than CMD_MAX commands are specified.
+ * ERR_CMD_OR_ARGS_TOO_BIG if the executable or argument string exceeds its size.
+ */
+int build_cmd_list(char *cmd_line, command_list_t *clist)
+{
+ clist->num = 0;
+ char *saveptr1;
+ /* Use strtok_r to split the command line by the pipe '|' character */
+ char *token = strtok_r(cmd_line, PIPE_STRING, &saveptr1);
+ while (token != NULL) {
+ char *trimmed = trim(token);
+ if (strlen(trimmed) == 0) {
+ token = strtok_r(NULL, PIPE_STRING, &saveptr1);
+ continue;
+ }
+
+ if (clist->num >= CMD_MAX) {
+ return ERR_TOO_MANY_COMMANDS;
+ }
+
+ char command_buffer[SH_CMD_MAX];
+ strncpy(command_buffer, trimmed, sizeof(command_buffer) - 1);
+ command_buffer[sizeof(command_buffer) - 1] = '\0';
+
+ char *saveptr2;
+ /* Use strtok_r to split the command_buffer by spaces */
+ char *arg = strtok_r(command_buffer, " ", &saveptr2);
+ if (arg == NULL) {
+ token = strtok_r(NULL, PIPE_STRING, &saveptr1);
+ continue;
+ }
+
+ if (strlen(arg) >= EXE_MAX) {
+ return ERR_CMD_OR_ARGS_TOO_BIG;
+ }
+ strcpy(clist->commands[clist->num].exe, arg);
+
+ /* Initialize the args string as empty */
+ clist->commands[clist->num].args[0] = '\0';
+
+ while ((arg = strtok_r(NULL, " ", &saveptr2)) != NULL) {
+ if (strlen(clist->commands[clist->num].args) + strlen(arg) >= ARG_MAX) {
+ return ERR_CMD_OR_ARGS_TOO_BIG;
+ }
+ strcat(clist->commands[clist->num].args, arg);
+ }
+
+ clist->num++;
+ token = strtok_r(NULL, PIPE_STRING, &saveptr1);
+ }
+
+ return OK;
+}
\ No newline at end of file
--
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