commit 5d06822349e135a141df1b6088c1e513ea28cbd9
Author: mjkloeckner <martinjkloeckner@gmail.com>
Date: Mon, 1 May 2023 23:55:43 -0300
first commit
Diffstat:
| A | Makefile | | | 20 | ++++++++++++++++++++ |
| A | msh.c | | | 103 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
2 files changed, 123 insertions(+), 0 deletions(-)
diff --git a/Makefile b/Makefile
@@ -0,0 +1,20 @@
+CC := gcc
+CFLAGS := -Wall -Wshadow -pedantic -ansi -std=c99
+SRCS := $(wildcard *.c)
+OBJS := $(SRCS:.c=.o)
+
+TARGET := msh
+
+.PHONY: all clean
+
+all: $(TARGET)
+
+$(TARGET): $(OBJS)
+ $(CC) $(CLIBS) $(CFLAGS) -o $@ $^
+ rm -f $(OBJS)
+
+%.o: %.c
+ $(CC) $(CLIBS) $(CFLAGS) -c $< -o $@
+
+clean:
+ rm -f $(OBJS)
diff --git a/msh.c b/msh.c
@@ -0,0 +1,103 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+#define READLINE_BUFFER_INIT_SIZE 1000
+#define READLINE_BUFFER_GROWTH_FACTOR 0.5f
+#define TOKENS_BUFFER_INIT_SIZE 16
+
+static bool run = true;
+static size_t alloc_len;
+
+void buffer_clear(char *buf, size_t *len) {
+ for (size_t i = 0; i < *len; i++)
+ buf[i] = '\0';
+
+ *len = 0;
+}
+
+void buffer_read_line(char *buffer, size_t *len) {
+ int c;
+ char *tmp;
+
+ /* read line into buffer */
+ while(1) {
+ c = fgetc(stdin);
+ if((c == '\n') || (c == EOF)) break;
+
+ if((*len + 2 == alloc_len)) {
+ alloc_len += alloc_len * READLINE_BUFFER_GROWTH_FACTOR;
+ if((tmp = realloc(buffer, alloc_len)) == NULL) return;
+ buffer = tmp;
+ }
+
+ buffer[(*len)++] = c;
+ }
+ buffer[*len] = '\0';
+ if (c == EOF) run = false;
+}
+
+void buffer_split(char *b, size_t *len, char ***tokens, size_t *tokens_count) {
+ if(b == NULL) return;
+
+ size_t token_alloc;
+ char *start, **tmp;
+
+ start = b;
+ *tokens_count = 0;
+
+ if(*tokens != NULL) return;
+
+ *tokens = malloc((sizeof(char *) * TOKENS_BUFFER_INIT_SIZE));
+ token_alloc = TOKENS_BUFFER_INIT_SIZE;
+ if (*tokens == NULL) return;
+
+ (*tokens)[*tokens_count] = strtok(b, " ");
+ while((*tokens)[*tokens_count] != NULL) {
+ (*tokens)[++(*tokens_count)] = strtok(NULL, " ");
+ if (*tokens_count == token_alloc) {
+ token_alloc += TOKENS_BUFFER_INIT_SIZE;
+ tmp = realloc(*tokens, sizeof(char *) * token_alloc);
+ if(tmp == NULL) return;
+ *tokens = tmp;
+ }
+ }
+
+ b = start;
+}
+
+void msh_loop(void) {
+ char *buffer;
+ size_t len;
+
+ len = 0;
+ buffer = malloc(alloc_len = READLINE_BUFFER_INIT_SIZE);
+
+ while (run) {
+ buffer_clear(buffer, &len);
+
+ printf("> ");
+
+ buffer_read_line(buffer, &len);
+
+ /* printf("%s\n", buffer); */
+
+ char **tokens = NULL;
+ size_t tokens_count = 0;
+ buffer_split(buffer, &len, &tokens, &tokens_count);
+
+ printf("tokens_count: %ld\n", tokens_count);
+ for(size_t t = 0; t < tokens_count; t++)
+ printf("%s\n", tokens[t]);
+ }
+}
+
+int main (void) {
+ /* load config files */
+
+ msh_loop();
+
+ /* cleanup */
+ return 0;
+}
