config.c: add git_env_ulong() to parse environment variable

The new function parses an integeral value that fits in unsigned
long in human readable form, i.e. possibly with unit suffix, e.g.
10k = 10240, etc., from an environment variable.  Parsing of
GIT_MMAP_LIMIT and GIT_ALLOC_LIMIT will use it in later patches.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/cache.h b/cache.h
index fcb511db70f7703f2b29dbc89dcf703065c823fe..b820b6adc186b59b001cb52d158bb52724e4e509 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -1318,6 +1318,7 @@ extern int git_config_rename_section_in_file(const char *, const char *, const c
 extern const char *git_etc_gitconfig(void);
 extern int check_repository_format_version(const char *var, const char *value, void *cb);
 extern int git_env_bool(const char *, int);
+extern unsigned long git_env_ulong(const char *, unsigned long);
 extern int git_config_system(void);
 extern int config_error_nonbool(const char *);
 #if defined(__GNUC__)

diff --git a/config.c b/config.c
index 058505cb8d8d8bb531527b620125b0204732458a..adab91909eb0a7c817450971099a72798f8b8c01 100644 (file)
--- a/config.c
+++ b/config.c
@@ -1116,12 +1116,28 @@ const char *git_etc_gitconfig(void)
        return system_wide;
 }
 
+/*
+ * Parse environment variable 'k' as a boolean (in various
+ * possible spellings); if missing, use the default value 'def'.
+ */
 int git_env_bool(const char *k, int def)
 {
        const char *v = getenv(k);
        return v ? git_config_bool(k, v) : def;
 }
 
+/*
+ * Parse environment variable 'k' as ulong with possibly a unit
+ * suffix; if missing, use the default value 'val'.
+ */
+unsigned long git_env_ulong(const char *k, unsigned long val)
+{
+       const char *v = getenv(k);
+       if (v && !git_parse_ulong(v, &val))
+               die("failed to parse %s", k);
+       return val;
+}
+
 int git_config_system(void)
 {
        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);