Merge pull request #60 from fischerling/add-err

Add err function family to libc

libc/CMakeLists.txt

@@ -5,6 +5,7 @@
 # Add the library.
 add_library(
     libc
+    ${CMAKE_SOURCE_DIR}/libc/src/err.c
     ${CMAKE_SOURCE_DIR}/libc/src/shadow.c
     ${CMAKE_SOURCE_DIR}/libc/src/unistd/dup.c
     ${CMAKE_SOURCE_DIR}/libc/src/stdio.c

libc/inc/err.h

@@ -0,0 +1,20 @@
+/// @file err.h
+/// @brief Contains err functions
+/// @copyright (c) 2024 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#pragma once
+
+#include <stdarg.h>
+
+/// @brief Print formatted error message on stderr and exit
+/// @param eval The exit value.
+/// @param fmt  The format string.
+void err(int eval, const char *fmt, ...);
+void verr(int eval, const char *fmt, va_list args);
+
+/// @brief Print formatted message on stderr without appending an error message and exit
+/// @param eval The exit value.
+/// @param fmt  The format string.
+void errx(int eval, const char *fmt, ...);
+void verrx(int eval, const char *fmt, va_list args);

libc/inc/stdio.h

@@ -83,13 +83,21 @@ int printf(const char *fmt, ...);
 int sprintf(char *str, const char *fmt, ...);
 
 #ifndef __KERNEL__
-/// @brief The same as sprintf, but it putput on file.
+/// @brief Write formatted output to a file.
 /// @param fd  The file descriptor associated with the file.
 /// @param fmt  Format string, following the same specifications as printf.
 /// @param ... The list of arguments.
 /// @return On success, the total number of characters written is returned.
 ///         On failure, a negative number is returned.
 int fprintf(int fd, const char *fmt, ...);
+
+/// @brief Write formatted data from variable argument list to a file.
+/// @param fd  The file descriptor associated with the file.
+/// @param fmt  Format string, following the same specifications as printf.
+/// @param args A variable arguments list.
+/// @return On success, the total number of characters written is returned.
+///         On failure, a negative number is returned.
+int vfprintf(int fd, const char *fmt, va_list args);
 #endif
 
 /// @brief Write formatted data from variable argument list to string.

libc/src/err.c

@@ -0,0 +1,42 @@
+/// @file err.h
+/// @brief Contains err functions
+/// @copyright (c) 2024 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+#include <err.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <sys/unistd.h>
+
+void verr(int status, const char *fmt, va_list ap)
+{
+	if (fmt) {
+		vfprintf(STDERR_FILENO, fmt, ap);
+		fprintf(STDERR_FILENO, ": ");
+	}
+	perror(0);
+	exit(status);
+}
+
+void verrx(int status, const char *fmt, va_list ap)
+{
+	if (fmt) vfprintf(STDERR_FILENO, fmt, ap);
+	fprintf(STDERR_FILENO, "\n");
+	exit(status);
+}
+
+void err(int status, const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	verr(status, fmt, ap);
+	va_end(ap);
+}
+
+void errx(int status, const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	verrx(status, fmt, ap);
+	va_end(ap);
+}

libc/src/vsprintf.c

@@ -690,14 +690,10 @@ int sprintf(char *str, const char *fmt, ...)
     return len;
 }
 
-int fprintf(int fd, const char *fmt, ...)
+int vfprintf(int fd, const char *fmt, va_list args)
 {
     char buffer[4096];
-    va_list ap;
-
-    va_start(ap, fmt);
-    int len = vsprintf(buffer, fmt, ap);
-    va_end(ap);
+    int len = vsprintf(buffer, fmt, args);
 
     if (len > 0) {
         if (write(fd, buffer, len) <= 0) {
@@ -707,3 +703,13 @@ int fprintf(int fd, const char *fmt, ...)
     }
     return -1;
 }
+
+int fprintf(int fd, const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    int ret = vfprintf(fd, fmt, ap);
+    va_end(ap);
+
+    return ret;
+}