examples/common.h

   1 /*
   2  * Utilities library for libgit2 examples
   3  *
   4  * Written by the libgit2 contributors
   5  *
   6  * To the extent possible under law, the author(s) have dedicated all copyright
   7  * and related and neighboring rights to this software to the public domain
   8  * worldwide. This software is distributed without any warranty.
   9  *
  10  * You should have received a copy of the CC0 Public Domain Dedication along
  11  * with this software. If not, see
  12  * <http://creativecommons.org/publicdomain/zero/1.0/>.
  13  */
  14
  15 #include <stdio.h>
  16 #include <string.h>
  17 #include <stdlib.h>
  18 #include <git2.h>
  19
  20 /**
  21  * Check libgit2 error code, printing error to stderr on failure and
  22  * exiting the program.
  23  */
  24 extern void check_lg2(int error, const char *message, const char *extra);
  25
  26 /**
  27  * Exit the program, printing error to stderr
  28  */
  29 extern void fatal(const char *message, const char *extra);
  30
  31 /**
  32  * Check if a string has the given prefix.  Returns 0 if not prefixed
  33  * or the length of the prefix if it is.
  34  */
  35 extern size_t is_prefixed(const char *str, const char *pfx);
  36
  37 /**
  38  * Match an integer string, returning 1 if matched, 0 if not.
  39  */
  40 extern int is_integer(int *out, const char *str, int allow_negative);
  41
  42 struct args_info {
  43         int    argc;
  44         char **argv;
  45         int    pos;
  46 };
  47 #define ARGS_INFO_INIT { argc, argv, 0 }
  48
  49 /**
  50  * Check current `args` entry against `opt` string.  If it matches
  51  * exactly, take the next arg as a string; if it matches as a prefix with
  52  * an equal sign, take the remainder as a string; if value not supplied,
  53  * default value `def` will be given. otherwise return 0.
  54  */
  55 extern int optional_str_arg(
  56         const char **out, struct args_info *args, const char *opt, const char *def);
  57
  58 /**
  59  * Check current `args` entry against `opt` string.  If it matches
  60  * exactly, take the next arg as a string; if it matches as a prefix with
  61  * an equal sign, take the remainder as a string; otherwise return 0.
  62  */
  63 extern int match_str_arg(
  64         const char **out, struct args_info *args, const char *opt);
  65
  66 /**
  67  * Check current `args` entry against `opt` string parsing as uint16.  If
  68  * `opt` matches exactly, take the next arg as a uint16_t value; if `opt`
  69  * is a prefix (equal sign optional), take the remainder of the arg as a
  70  * uint16_t value; otherwise return 0.
  71  */
  72 extern int match_uint16_arg(
  73         uint16_t *out, struct args_info *args, const char *opt);
  74
  75 /**
  76  * Check current `args` entry against `opt` string parsing as uint32.  If
  77  * `opt` matches exactly, take the next arg as a uint16_t value; if `opt`
  78  * is a prefix (equal sign optional), take the remainder of the arg as a
  79  * uint32_t value; otherwise return 0.
  80  */
  81 extern int match_uint32_arg(
  82         uint32_t *out, struct args_info *args, const char *opt);
  83
  84 /**
  85  * Check current `args` entry against `opt` string parsing as int.  If
  86  * `opt` matches exactly, take the next arg as an int value; if it matches
  87  * as a prefix (equal sign optional), take the remainder of the arg as a
  88  * int value; otherwise return 0.
  89  */
  90 extern int match_int_arg(
  91         int *out, struct args_info *args, const char *opt, int allow_negative);
  92
  93 /**
  94  * Basic output function for plain text diff output
  95  * Pass `FILE*` such as `stdout` or `stderr` as payload (or NULL == `stdout`)
  96  */
  97 extern int diff_output(
  98         const git_diff_delta*, const git_diff_hunk*, const git_diff_line*, void*);
  99
 100 /**
 101  * Convert a treeish argument to an actual tree; this will call check_lg2
 102  * and exit the program if `treeish` cannot be resolved to a tree
 103  */
 104 extern void treeish_to_tree(
 105         git_tree **out, git_repository *repo, const char *treeish);
 106
 107 /**
 108  * A realloc that exits on failure
 109  */
 110 extern void *xrealloc(void *oldp, size_t newsz);