Added files.

3 files changed, 251 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..4dcc90a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,58 @@
+# Compiler and flags
+CC = gcc
+CFLAGS = -Wall -O2
+
+# Source and target names
+TARGET = chproc
+SRC = $(TARGET).c
+PRE = $(TARGET).i
+ASM = $(TARGET).s
+OBJ = $(TARGET).o
+
+# Example argument for test
+ARG = --list init
+
+# Default: build executable
+all: $(TARGET)
+
+# Stage 1: Preprocess
+$(PRE): $(SRC)
+	$(CC) -E $(CFLAGS) $< -o $@
+
+# Stage 2: Compile to assembly
+$(ASM): $(PRE)
+	$(CC) -S $(CFLAGS) $< -o $@
+
+# Stage 3: Assemble to object file
+$(OBJ): $(ASM)
+	$(CC) -c $(CFLAGS) $< -o $@
+
+# Stage 4: Link object to executable
+$(TARGET): $(OBJ)
+	$(CC) $(CFLAGS) $< -o $@
+
+# Run tests
+define run_test
+	@name="$(1) $(2)"; \
+	width=40; \
+	printf "%s" "$$name"; \
+	dots=$$((width - $${#name})); \
+	for i in $$(seq 1 $$dots); do printf "."; done; \
+	./$(TARGET) $(2) >/dev/null 2>&1; \
+	ec=$$?; \
+	if [ $$ec -eq 0 ] || [ $$ec -eq 2 ]; then \
+		echo " OK"; \
+	else \
+		echo " FAILED (exit $$ec)"; \
+		exit 1; \
+	fi
+endef
+
+test: $(TARGET)
+	$(call run_test,$(TARGET) no args,)
+	$(call run_test,$(TARGET),$(ARG),)
+
+# Clean all generated files
+clean:
+	rm -v -f $(PRE) $(ASM) $(OBJ) $(TARGET)
+
diff --git a/Makefile.clang b/Makefile.clang
new file mode 100755
index 0000000..e275c31
--- /dev/null
+++ b/Makefile.clang
@@ -0,0 +1 @@
+clang -Weverything -o chproc_clang chproc.c
diff --git a/chproc.c b/chproc.c
new file mode 100644
index 0000000..6d407fb
--- /dev/null
+++ b/chproc.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * chproc.c - simple process checker
+ *
+ * Iterate over /proc and print PIDs of processes matching the given name.
+ */
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <ctype.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <limits.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <getopt.h>
+#include <signal.h>
+#include <stdbool.h>
+
+#define PROGRAM_NAME "chproc"
+
+struct options {
+	int list;
+	int kill;
+	char *process_name;
+	char *process_pid;
+};
+
+
+static void options_init(struct options *x)
+{
+	x->list = false;
+	x->kill = false;
+	x->process_pid = NULL;
+	x->process_name = NULL;
+}
+
+
+static void usage(void)
+{
+	fprintf(stderr,
+		"Usage: %s <option> [process_name, pid]\n"
+		" -l, --list <name>	list all PID of that process\n"
+		" -k, --kill <PID>	kill a proces give then PID\n"
+		, PROGRAM_NAME);
+}
+
+
+
+static int process_list(DIR *dir,
+		const char *proc_name)
+{
+	char path[PATH_MAX];
+	char buffer[256];
+	char *endptr;
+	FILE *f;
+	int count;
+	long pid;
+	struct dirent *entry;
+	size_t len;
+
+	count = 0;
+
+	while ((entry = readdir(dir)) != NULL) {
+		/* skip "." and ".." */
+		if (strcmp(entry->d_name, ".") == 0)
+			continue;
+		if (strcmp(entry->d_name, "..") == 0)
+			continue;
+
+
+		pid = strtol(entry->d_name, &endptr, 10);
+
+		if (*endptr != '\0') /* not a pure number */
+			continue;
+
+		snprintf(path, sizeof(path), "/proc/%ld/comm", pid);
+
+		f = fopen(path, "r");
+
+		if (!f) {
+			fprintf(stderr, "Failed to open %s: %s\n",
+				path, strerror(errno));
+			continue;
+		}
+
+		if (fgets(buffer, sizeof(buffer), f)) {
+			len = strlen(buffer);
+
+			if (len > 0 && buffer[len-1] == '\n')
+				buffer[len-1] = '\0';
+
+			if (strcmp(buffer, proc_name) == 0) {
+				printf("%s - %s\n", entry->d_name, buffer);
+				++count;
+			}
+		}
+		fclose(f);
+	}
+
+	closedir(dir);
+
+	if (count == 0)
+		return 1;
+	else
+		return 0;
+}
+
+
+static int process_kill(const char *process_id)
+{
+	pid_t pid;
+
+	if (atoi(process_id) < 1) {
+		fprintf(stderr, "'%s': not a pid or valid job\n", process_id);
+		usage();
+		return 1;
+	}
+
+	pid = (pid_t) atoi(process_id);
+
+	if (kill(pid, SIGTERM) == -1) {
+		perror("kill failed");
+		return 1;
+	}
+
+	printf("Process '%d' killed.\n", pid);
+	return 0;
+}
+
+
+int main(int argc, char *argv[])
+{
+	int opt;
+	DIR *dir_proc;
+
+	struct options x;
+
+	struct option long_options[] = {
+		{"list", required_argument, 0, 'l'},
+		{"kill", required_argument, 0, 'k'},
+		{0, 0, 0, 0}
+	};
+
+	options_init(&x);
+
+	/* /proc/ must to exist */
+	dir_proc = opendir("/proc");
+	if (dir_proc == NULL) {
+		fprintf(stderr, "/proc/ not found.\n");
+		return EXIT_FAILURE;
+	}
+
+	if (argc < 3) {
+		usage();
+		return 2;
+	}
+
+	while ((opt = getopt_long(argc, argv, "l:k:",
+		long_options, NULL)) != -1) {
+		switch (opt) {
+		case 'l':
+			x.list = true;
+			x.process_name = optarg;
+			break;
+		case 'k':
+			x.kill = true;
+			x.process_pid = optarg;
+			break;
+		default:
+			fprintf(stderr,
+				"Unknow option.\n");
+			usage();
+			exit(2);
+		}
+	}
+
+	if (x.list)
+		if (process_list(dir_proc, x.process_name) == 1)
+			return 1;
+
+	if (x.kill)
+		if (process_kill(x.process_pid) == 1)
+			return 1;
+
+	return 0;
+}
+
+
+