safewrappers.c

/*
 * vim:ts=4:sw=4:expandtab
 *
 * i3 - an improved dynamic tiling window manager
 * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
 *
 */
#include "libi3.h"

#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <stdio.h>
#include <err.h>
#include <errno.h>

/*
 * The s* functions (safe) are wrappers around malloc, strdup, …, which exits if one of
 * the called functions returns NULL, meaning that there is no more memory available
 *
 */
void *smalloc(size_t size) {
    void *result = malloc(size);
    if (result == NULL)
        err(EXIT_FAILURE, "malloc(%zd)", size);
    return result;
}

void *scalloc(size_t num, size_t size) {
    void *result = calloc(num, size);
    if (result == NULL)
        err(EXIT_FAILURE, "calloc(%zd, %zd)", num, size);
    return result;
}

void *srealloc(void *ptr, size_t size) {
    void *result = realloc(ptr, size);
    if (result == NULL && size > 0)
        err(EXIT_FAILURE, "realloc(%zd)", size);
    return result;
}

char *sstrdup(const char *str) {
    char *result = strdup(str);
    if (result == NULL)
        err(EXIT_FAILURE, "strdup()");
    return result;
}

char *sstrndup(const char *str, size_t size) {
    char *result = strndup(str, size);
    if (result == NULL)
        err(EXIT_FAILURE, "strndup()");
    return result;
}

int sasprintf(char **strp, const char *fmt, ...) {
    va_list args;
    int result;

    va_start(args, fmt);
    if ((result = vasprintf(strp, fmt, args)) == -1)
        err(EXIT_FAILURE, "asprintf(%s)", fmt);
    va_end(args);
    return result;
}

ssize_t writeall(int fd, const void *buf, size_t count) {
    size_t written = 0;

    while (written < count) {
        const ssize_t n = write(fd, ((char *)buf) + written, count - written);
        if (n == -1) {
            if (errno == EINTR || errno == EAGAIN)
                continue;
            return n;
        }
        written += (size_t)n;
    }

    return written;
}

ssize_t writeall_nonblock(int fd, const void *buf, size_t count) {
    size_t written = 0;

    while (written < count) {
        const ssize_t n = write(fd, ((char *)buf) + written, count - written);
        if (n == -1) {
            if (errno == EAGAIN) {
                return written;
            } else if (errno == EINTR) {
                continue;
            } else {
                return n;
            }
        }
        written += (size_t)n;
    }
    return written;
}

ssize_t swrite(int fd, const void *buf, size_t count) {
    ssize_t n;

    n = writeall(fd, buf, count);
    if (n == -1)
        err(EXIT_FAILURE, "Failed to write %d", fd);
    else
        return n;
}

/*
 * Like strcasecmp but considers the case where either string is NULL.
 *
 */
int strcasecmp_nullable(const char *a, const char *b) {
    if (a == b) {
        return 0;
    }
    if (a == NULL) {
        return -1;
    }
    if (b == NULL) {
        return 1;
    }
    return strcasecmp(a, b);
}