A common usage pattern of fopen() is to check if it succeeded, and die()
if it failed:

        FILE *fp = fopen(path, "w");
        if (!fp)
                die_errno(_("could not open '%s' for writing"), path);

Implement a wrapper function xfopen() for the above, so that we can save
a few lines of code and make the die() messages consistent.

Helped-by: Jeff King <p...@peff.net>
Helped-by: Johannes Schindelin <johannes.schinde...@gmx.de>
Helped-by: Junio C Hamano <gits...@pobox.com>
Signed-off-by: Paul Tan <pyoka...@gmail.com>
---
 git-compat-util.h |  1 +
 wrapper.c         | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/git-compat-util.h b/git-compat-util.h
index e168dfd..392da79 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -722,6 +722,7 @@ extern ssize_t xread(int fd, void *buf, size_t len);
 extern ssize_t xwrite(int fd, const void *buf, size_t len);
 extern ssize_t xpread(int fd, void *buf, size_t len, off_t offset);
 extern int xdup(int fd);
+extern FILE *xfopen(const char *path, const char *mode);
 extern FILE *xfdopen(int fd, const char *mode);
 extern int xmkstemp(char *template);
 extern int xmkstemp_mode(char *template, int mode);
diff --git a/wrapper.c b/wrapper.c
index 0a4502d..e451463 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -346,6 +346,27 @@ int xdup(int fd)
        return ret;
 }
 
+/**
+ * xfopen() is the same as fopen(), but it die()s if the fopen() fails.
+ */
+FILE *xfopen(const char *path, const char *mode)
+{
+       for (;;) {
+               FILE *fp = fopen(path, mode);
+               if (fp)
+                       return fp;
+               if (errno == EINTR)
+                       continue;
+
+               if (*mode && mode[1] == '+')
+                       die_errno(_("could not open '%s' for reading and 
writing"), path);
+               else if (*mode == 'w' || *mode == 'a')
+                       die_errno(_("could not open '%s' for writing"), path);
+               else
+                       die_errno(_("could not open '%s' for reading"), path);
+       }
+}
+
 FILE *xfdopen(int fd, const char *mode)
 {
        FILE *stream = fdopen(fd, mode);
-- 
2.5.0.280.gd88bd6e

--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to