builtin-merge-file.con commit user-manual: Explain what submodules are good for. (6dd1436)
   1#include "builtin.h"
   2#include "cache.h"
   3#include "xdiff/xdiff.h"
   4#include "xdiff-interface.h"
   5
   6static const char merge_file_usage[] =
   7"git merge-file [-p | --stdout] [-q | --quiet] [-L name1 [-L orig [-L name2]]] file1 orig_file file2";
   8
   9int cmd_merge_file(int argc, const char **argv, const char *prefix)
  10{
  11        const char *names[3];
  12        mmfile_t mmfs[3];
  13        mmbuffer_t result = {NULL, 0};
  14        xpparam_t xpp = {XDF_NEED_MINIMAL};
  15        int ret = 0, i = 0, to_stdout = 0;
  16
  17        while (argc > 4) {
  18                if (!strcmp(argv[1], "-L") && i < 3) {
  19                        names[i++] = argv[2];
  20                        argc--;
  21                        argv++;
  22                } else if (!strcmp(argv[1], "-p") ||
  23                                !strcmp(argv[1], "--stdout"))
  24                        to_stdout = 1;
  25                else if (!strcmp(argv[1], "-q") ||
  26                                !strcmp(argv[1], "--quiet"))
  27                        freopen("/dev/null", "w", stderr);
  28                else
  29                        usage(merge_file_usage);
  30                argc--;
  31                argv++;
  32        }
  33
  34        if (argc != 4)
  35                usage(merge_file_usage);
  36
  37        for (; i < 3; i++)
  38                names[i] = argv[i + 1];
  39
  40        for (i = 0; i < 3; i++) {
  41                if (read_mmfile(mmfs + i, argv[i + 1]))
  42                        return -1;
  43                if (buffer_is_binary(mmfs[i].ptr, mmfs[i].size))
  44                        return error("Cannot merge binary files: %s\n",
  45                                        argv[i + 1]);
  46        }
  47
  48        ret = xdl_merge(mmfs + 1, mmfs + 0, names[0], mmfs + 2, names[2],
  49                        &xpp, XDL_MERGE_ZEALOUS, &result);
  50
  51        for (i = 0; i < 3; i++)
  52                free(mmfs[i].ptr);
  53
  54        if (ret >= 0) {
  55                const char *filename = argv[1];
  56                FILE *f = to_stdout ? stdout : fopen(filename, "wb");
  57
  58                if (!f)
  59                        ret = error("Could not open %s for writing", filename);
  60                else if (fwrite(result.ptr, result.size, 1, f) != 1)
  61                        ret = error("Could not write to %s", filename);
  62                else if (fclose(f))
  63                        ret = error("Could not close %s", filename);
  64                free(result.ptr);
  65        }
  66
  67        return ret;
  68}