diff options
| -rw-r--r-- | completions/bfs.bash | 3 | ||||
| -rw-r--r-- | completions/bfs.fish | 1 | ||||
| -rw-r--r-- | completions/bfs.zsh | 1 | ||||
| -rw-r--r-- | docs/USAGE.md | 34 | ||||
| -rw-r--r-- | docs/bfs.1 | 5 | ||||
| -rw-r--r-- | src/eval.c | 13 | ||||
| -rw-r--r-- | src/eval.h | 1 | ||||
| -rw-r--r-- | src/opt.c | 1 | ||||
| -rw-r--r-- | src/parse.c | 38 | ||||
| -rw-r--r-- | tests/bfs/limit.out | 4 | ||||
| -rw-r--r-- | tests/bfs/limit.sh | 1 | ||||
| -rw-r--r-- | tests/bfs/limit_0.sh | 1 | ||||
| -rw-r--r-- | tests/bfs/limit_implicit_print.sh | 1 | ||||
| -rw-r--r-- | tests/bfs/limit_incomplete.sh | 1 | ||||
| -rw-r--r-- | tests/bfs/limit_one.sh | 1 |
15 files changed, 103 insertions, 3 deletions
diff --git a/completions/bfs.bash b/completions/bfs.bash index 2f52e8d..db582da 100644 --- a/completions/bfs.bash +++ b/completions/bfs.bash @@ -37,6 +37,7 @@ _bfs() { -ipath -iregex -iwholename + -limit -links -lname -maxdepth @@ -94,8 +95,6 @@ _bfs() { -depth -follow -ignore_readdir_race - -maxdepth - -mindepth -mount -nocolor -noignore_readdir_race diff --git a/completions/bfs.fish b/completions/bfs.fish index 3f399e7..1303639 100644 --- a/completions/bfs.fish +++ b/completions/bfs.fish @@ -133,6 +133,7 @@ complete -c bfs -o fls -d "Like -ls, but write to specified file" -F complete -c bfs -o fprint -d "Like -print, but write to specified file" -F complete -c bfs -o fprint0 -d "Like -print0, but write to specified file" -F complete -c bfs -o fprintf -d "Like -printf, but write to specified file" -F +complete -c bfs -o limit -d "Limit the number of results" -x complete -c bfs -o ls -d "List files like ls -dils" complete -c bfs -o print -d "Print the path to the found file" complete -c bfs -o print0 -d "Like -print, but use the null character as a separator rather than newlines" diff --git a/completions/bfs.zsh b/completions/bfs.zsh index 3d7dc3a..51b5029 100644 --- a/completions/bfs.zsh +++ b/completions/bfs.zsh @@ -133,6 +133,7 @@ args=( '*-fprint0[print the path to the found file using null character as separator, but write to FILE instead of standard output]:output file:_files' '*-fprintf[print according to format string, but write to FILE instead of standard output]:output file:_files:output format' + '*-limit[quit after N results]:maximum result count' '*-ls[list files like ls -dils]' '*-print[print the path to the found file]' '*-print0[print the path to the found file using null character as separator]' diff --git a/docs/USAGE.md b/docs/USAGE.md index 3efdee0..071c95b 100644 --- a/docs/USAGE.md +++ b/docs/USAGE.md @@ -130,6 +130,40 @@ Unlike `-prune`, `-exclude` even works in combination with `-depth`/`-delete`. --- +### `-limit` + +The `-limit N` action makes `bfs` quit once it gets evaluated `N` times. +Placing it after an action like `-print` limits the number of results that get printed, for example: + +```console +$ bfs -s -type f -name '*.txt' +./1.txt +./2.txt +./3.txt +./4.txt +$ bfs -s -type f -name '*.txt' -print -limit 2 +./1.txt +./2.txt +``` + +This is similar to + +```console +$ bfs -s -type f -name '*.txt' | head -n2 +``` + +but more powerful because you can apply separate limits to different expressions: + +```console +$ bfs \( -name '*.txt' -print -limit 3 -o -name '*.log' -print -limit 4 \) -limit 5 +[At most 3 .txt files, at most 4 .log files, and at most 5 in total] +``` + +and more efficient because it will quit immediately. +When piping to `head`, `bfs` will only quit *after* it tries to output too many results. + +--- + ### `-hidden`/`-nohidden` `-hidden` matches "hidden" files (dotfiles). @@ -725,6 +725,11 @@ but write to instead of standard output. .RE .TP +\fB\-limit \fIN\fR +Quit once this action is evaluated +.I N +times. +.TP .B \-ls List files like .B ls @@ -841,6 +841,19 @@ error: } /** + * -limit action. + */ +bool eval_limit(const struct bfs_expr *expr, struct bfs_eval *state) { + long long evals = expr->evaluations + 1; + if (evals >= expr->num) { + state->action = BFTW_STOP; + state->quit = true; + } + + return true; +} + +/** * -prune action. */ bool eval_prune(const struct bfs_expr *expr, struct bfs_eval *state) { @@ -88,6 +88,7 @@ bool eval_fprint(const struct bfs_expr *expr, struct bfs_eval *state); bool eval_fprint0(const struct bfs_expr *expr, struct bfs_eval *state); bool eval_fprintf(const struct bfs_expr *expr, struct bfs_eval *state); bool eval_fprintx(const struct bfs_expr *expr, struct bfs_eval *state); +bool eval_limit(const struct bfs_expr *expr, struct bfs_eval *state); bool eval_prune(const struct bfs_expr *expr, struct bfs_eval *state); bool eval_quit(const struct bfs_expr *expr, struct bfs_eval *state); @@ -1181,6 +1181,7 @@ static struct bfs_expr *annotate_visit(struct bfs_opt *opt, struct bfs_expr *exp eval_fprint0, eval_fprintf, eval_fprintx, + eval_limit, eval_prune, eval_true, // Non-returning diff --git a/src/parse.c b/src/parse.c index 3b7386d..2dfcab2 100644 --- a/src/parse.c +++ b/src/parse.c @@ -97,6 +97,8 @@ struct bfs_parser { char **last_arg; /** A "-depth"-type argument, if any. */ char **depth_arg; + /** A "-limit" argument, if any. */ + char **limit_arg; /** A "-prune" argument, if any. */ char **prune_arg; /** A "-mount" argument, if any. */ @@ -733,7 +735,7 @@ static struct bfs_expr *parse_action(struct bfs_parser *parser, bfs_eval_fn *eva return NULL; } - if (eval_fn != eval_prune && eval_fn != eval_quit) { + if (eval_fn != eval_limit && eval_fn != eval_prune && eval_fn != eval_quit) { parser->implicit_print = false; } @@ -1570,6 +1572,29 @@ static struct bfs_expr *parse_jobs(struct bfs_parser *parser, int arg1, int arg2 } /** + * Parse -limit N. + */ +static struct bfs_expr *parse_limit(struct bfs_parser *parser, int arg1, int arg2) { + struct bfs_expr *expr = parse_unary_action(parser, eval_limit); + if (!expr) { + return NULL; + } + + char **arg = &expr->argv[1]; + if (!parse_int(parser, arg, *arg, &expr->num, IF_LONG_LONG)) { + return NULL; + } + + if (expr->num <= 0) { + parse_expr_error(parser, expr, "The ${blu}%s${rs} must be at least ${bld}1${rs}.\n", expr->argv[0]); + return NULL; + } + + parser->limit_arg = expr->argv; + return expr; +} + +/** * Parse -links N. */ static struct bfs_expr *parse_links(struct bfs_parser *parser, int arg1, int arg2) { @@ -2845,6 +2870,8 @@ static struct bfs_expr *parse_help(struct bfs_parser *parser, int arg1, int arg2 cfprintf(cout, " ${blu}-fprintf${rs} ${bld}FILE${rs} ${bld}FORMAT${rs}\n"); cfprintf(cout, " Like ${blu}-ls${rs}/${blu}-print${rs}/${blu}-print0${rs}/${blu}-printf${rs}, but write to ${bld}FILE${rs} instead of standard\n" " output\n"); + cfprintf(cout, " ${blu}-limit${rs} ${bld}N${rs}\n"); + cfprintf(cout, " Quit after this action is evaluated ${bld}N${rs} times\n"); cfprintf(cout, " ${blu}-ls${rs}\n"); cfprintf(cout, " List files like ${ex}ls${rs} ${bld}-dils${rs}\n"); cfprintf(cout, " ${blu}-print${rs}\n"); @@ -2968,6 +2995,7 @@ static const struct table_entry parse_table[] = { {"-iregex", T_TEST, parse_regex, BFS_REGEX_ICASE}, {"-iwholename", T_TEST, parse_path, true}, {"-j", T_FLAG, parse_jobs, 0, 0, true}, + {"-limit", T_ACTION, parse_limit}, {"-links", T_TEST, parse_links}, {"-lname", T_TEST, parse_lname, false}, {"-ls", T_ACTION, parse_ls}, @@ -3330,6 +3358,14 @@ static struct bfs_expr *parse_whole_expr(struct bfs_parser *parser) { } if (parser->implicit_print) { + char **limit = parser->limit_arg; + if (limit) { + parse_argv_error(parser, parser->limit_arg, 2, + "With ${blu}%s${rs}, you must specify an action explicitly; for example, ${blu}-print${rs} ${blu}%s${rs} ${bld}%s${rs}.\n", + limit[0], limit[0], limit[1]); + return NULL; + } + struct bfs_expr *print = parse_new_expr(parser, eval_fprint, 1, &fake_print_arg); if (!print) { return NULL; diff --git a/tests/bfs/limit.out b/tests/bfs/limit.out new file mode 100644 index 0000000..ea94276 --- /dev/null +++ b/tests/bfs/limit.out @@ -0,0 +1,4 @@ +basic/a +basic/b +basic/c/d +basic/e/f diff --git a/tests/bfs/limit.sh b/tests/bfs/limit.sh new file mode 100644 index 0000000..84b605f --- /dev/null +++ b/tests/bfs/limit.sh @@ -0,0 +1 @@ +bfs_diff -s basic -type f -print -limit 4 diff --git a/tests/bfs/limit_0.sh b/tests/bfs/limit_0.sh new file mode 100644 index 0000000..3ce26de --- /dev/null +++ b/tests/bfs/limit_0.sh @@ -0,0 +1 @@ +! invoke_bfs basic -print -limit 0 diff --git a/tests/bfs/limit_implicit_print.sh b/tests/bfs/limit_implicit_print.sh new file mode 100644 index 0000000..cdb059d --- /dev/null +++ b/tests/bfs/limit_implicit_print.sh @@ -0,0 +1 @@ +! invoke_bfs basic -type f -limit 1 diff --git a/tests/bfs/limit_incomplete.sh b/tests/bfs/limit_incomplete.sh new file mode 100644 index 0000000..2d1e842 --- /dev/null +++ b/tests/bfs/limit_incomplete.sh @@ -0,0 +1 @@ +! invoke_bfs basic -print -limit diff --git a/tests/bfs/limit_one.sh b/tests/bfs/limit_one.sh new file mode 100644 index 0000000..3f8181c --- /dev/null +++ b/tests/bfs/limit_one.sh @@ -0,0 +1 @@ +! invoke_bfs basic -print -limit one |