branch: say "Reset to" in reflog entries for 'git branch -f' operations
[git/jnareb-git.git] / interpolate.c
blobf992ef77533737fe2ec52dc3b662cb6cacca0ea2
1 /*
2 * Copyright 2006 Jon Loeliger
3 */
5 #include "git-compat-util.h"
6 #include "interpolate.h"
9 void interp_set_entry(struct interp *table, int slot, const char *value)
11 char *oldval = table[slot].value;
12 char *newval = NULL;
14 if (oldval)
15 free(oldval);
17 if (value)
18 newval = xstrdup(value);
20 table[slot].value = newval;
24 void interp_clear_table(struct interp *table, int ninterps)
26 int i;
28 for (i = 0; i < ninterps; i++) {
29 interp_set_entry(table, i, NULL);
35 * Convert a NUL-terminated string in buffer orig
36 * into the supplied buffer, result, whose length is reslen,
37 * performing substitutions on %-named sub-strings from
38 * the table, interps, with ninterps entries.
40 * Example interps:
41 * {
42 * { "%H", "example.org"},
43 * { "%port", "123"},
44 * { "%%", "%"},
45 * }
47 * Returns 1 on a successful substitution pass that fits in result,
48 * Returns 0 on a failed or overflowing substitution pass.
51 int interpolate(char *result, int reslen,
52 const char *orig,
53 const struct interp *interps, int ninterps)
55 const char *src = orig;
56 char *dest = result;
57 int newlen = 0;
58 char *name, *value;
59 int namelen, valuelen;
60 int i;
61 char c;
63 memset(result, 0, reslen);
65 while ((c = *src) && newlen < reslen - 1) {
66 if (c == '%') {
67 /* Try to match an interpolation string. */
68 for (i = 0; i < ninterps; i++) {
69 name = interps[i].name;
70 namelen = strlen(name);
71 if (strncmp(src, name, namelen) == 0) {
72 break;
76 /* Check for valid interpolation. */
77 if (i < ninterps) {
78 value = interps[i].value;
79 valuelen = strlen(value);
81 if (newlen + valuelen < reslen - 1) {
82 /* Substitute. */
83 strncpy(dest, value, valuelen);
84 newlen += valuelen;
85 dest += valuelen;
86 src += namelen;
87 } else {
88 /* Something's not fitting. */
89 return 0;
92 } else {
93 /* Skip bogus interpolation. */
94 *dest++ = *src++;
95 newlen++;
98 } else {
99 /* Straight copy one non-interpolation character. */
100 *dest++ = *src++;
101 newlen++;
105 return newlen < reslen - 1;