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ExpertcoderzExpertcoderz
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Standardize error handling
- Added `core.perror()` for displaying exceptions and error messages in the proper format. - Added `core.safe_open()` for catching exceptions when opening files.
1 parent 2c1fcd9 commit fe96e5a

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14 files changed

+100
-76
lines changed

14 files changed

+100
-76
lines changed

‎userland/core/io.py‎

Lines changed: 20 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,24 @@
1+
import contextlib
2+
import os
13
import sys
2-
from typing import Generator
4+
from typing import Any, Generator
5+
6+
7+
def perror(*errors: Any) -> None:
8+
print(
9+
f"{os.path.basename(sys.argv[0])}: {"\n".join(map(str, errors))}",
10+
file=sys.stderr,
11+
)
12+
13+
14+
@contextlib.contextmanager
15+
def safe_open(*args, **kwargs):
16+
try:
17+
with open(*args, **kwargs) as io:
18+
yield io
19+
except OSError as e:
20+
perror(e)
21+
yield None
322

423

524
def readlines_stdin() -> Generator[str]:

‎userland/utilities/cat.py‎

Lines changed: 13 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -146,10 +146,18 @@ def python_userland_cat(opts, args):
146146
opts.show_tabs = True
147147
opts.show_nonprinting = True
148148

149-
generators = [
150-
core.readlines_stdin_raw() if name == "-" else open(name, "rb")
151-
for name in args or ["-"]
152-
]
149+
generators: list[Generator[bytes]] = []
150+
failed = False
151+
152+
for name in args or ["-"]:
153+
if name == "-":
154+
generators.append(core.readlines_stdin_raw())
155+
else:
156+
io = core.safe_open(name, "rb")
157+
if io:
158+
generators.append(io)
159+
else:
160+
failed = True
153161

154162
try:
155163
cat_io(opts, itertools.chain(*generators))
@@ -162,4 +170,4 @@ def python_userland_cat(opts, args):
162170
if isinstance(gen, BufferedReader):
163171
gen.close()
164172

165-
return 0
173+
return int(failed)

‎userland/utilities/chgrp.py‎

Lines changed: 9 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -141,7 +141,7 @@ def python_userland_chgrp(opts, args):
141141
try:
142142
gid = Path(opts.reference).stat(follow_symlinks=True).st_gid
143143
except OSError as e:
144-
print(e, file=sys.stderr)
144+
core.perror(e)
145145
return 1
146146
else:
147147
parser.expect_nargs(args, (2,))
@@ -171,11 +171,12 @@ def python_userland_chgrp(opts, args):
171171
except OSError as e:
172172
failed = True
173173
if opts.verbosity:
174-
print(e, file=sys.stderr)
175-
print(
176-
f"failed to change group of '{file}' to {gname or gid}",
177-
file=sys.stderr,
178-
)
174+
core.perror(e)
175+
if opts.verbosity > 2:
176+
print(
177+
f"failed to change group of '{file}' to {gname or gid}",
178+
file=sys.stderr,
179+
)
179180
continue
180181

181182
prev_gname = core.group_display_name_from_id(prev_gid)
@@ -196,8 +197,8 @@ def python_userland_chgrp(opts, args):
196197
except OSError as e:
197198
failed = True
198199
if opts.verbosity:
199-
print(e, file=sys.stderr)
200-
if opts.verbosity:
200+
core.perror(e)
201+
if opts.verbosity > 2:
201202
print(
202203
f"failed to change group of '{file}' to {gname or gid}",
203204
file=sys.stderr,

‎userland/utilities/chown.py‎

Lines changed: 16 additions & 17 deletions
Original file line numberDiff line numberDiff line change
@@ -141,7 +141,7 @@ def python_userland_chown(opts, args):
141141
try:
142142
ref_stat = Path(opts.reference).stat(follow_symlinks=True)
143143
except OSError as e:
144-
print(e, file=sys.stderr)
144+
core.perror(e)
145145
return 1
146146

147147
chown_args["user"] = ref_stat.st_uid
@@ -154,14 +154,10 @@ def python_userland_chown(opts, args):
154154
parser.error(f"invalid owner spec: {owner_spec}")
155155

156156
chown_args["user"] = (
157-
parser.parse_user(owner_match.group(1))
158-
if owner_match.group(1)
159-
else None
157+
parser.parse_user(owner_match.group(1)) if owner_match.group(1) else None
160158
)
161159
chown_args["group"] = (
162-
parser.parse_group(owner_match.group(3))
163-
if owner_match.group(3)
164-
else None
160+
parser.parse_group(owner_match.group(3)) if owner_match.group(3) else None
165161
)
166162

167163
failed = False
@@ -181,11 +177,13 @@ def python_userland_chown(opts, args):
181177
prev_gid = stat.st_gid
182178
except OSError as e:
183179
failed = True
184-
print(e, file=sys.stderr)
185-
print(
186-
f"failed to change ownership of '{file}' to {owner_spec}",
187-
file=sys.stderr,
188-
)
180+
if opts.verbosity:
181+
core.perror(e)
182+
if opts.verbosity > 2:
183+
print(
184+
f"failed to change ownership of '{file}' to {owner_spec}",
185+
file=sys.stderr,
186+
)
189187
continue
190188

191189
prev_uname = core.user_display_name_from_id(prev_uid)
@@ -203,11 +201,12 @@ def python_userland_chown(opts, args):
203201
except OSError as e:
204202
failed = True
205203
if opts.verbosity:
206-
print(e, file=sys.stderr)
207-
print(
208-
f"failed to change ownership of '{file}' to {owner_spec}",
209-
file=sys.stderr,
210-
)
204+
core.perror(e)
205+
if opts.verbosity > 2:
206+
print(
207+
f"failed to change ownership of '{file}' to {owner_spec}",
208+
file=sys.stderr,
209+
)
211210
continue
212211

213212
if prev_uid == chown_args["user"] or prev_gid == chown_args["group"]:

‎userland/utilities/env.py‎

Lines changed: 2 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,5 @@
11
import os
22
import shlex
3-
import sys
43

54
from .. import core
65

@@ -87,15 +86,15 @@ def python_userland_env(opts, args):
8786
try:
8887
os.chdir(opts.chdir)
8988
except OSError as e:
90-
print(e, file=sys.stderr)
89+
core.perror(e)
9190
return 125
9291

9392
prog_args.insert(1, opts.argv0 if opts.argv0 else prog_args[0])
9493

9594
try:
9695
os.execvpe(prog_args[0], prog_args[1:], env)
9796
except OSError as e:
98-
print(e, file=sys.stderr)
97+
core.perror(e)
9998
return 126 if isinstance(e, FileNotFoundError) else 127
10099

101100
return 0

‎userland/utilities/factor.py‎

Lines changed: 1 addition & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,4 @@
11
import math
2-
import sys
32
from typing import Generator, Iterable
43

54
from .. import core
@@ -120,7 +119,7 @@ def python_userland_factor(opts, args):
120119
raise ValueError
121120
except ValueError:
122121
failed = True
123-
print(f"'{arg}' is not a valid positive integer", file=sys.stderr)
122+
core.perror(f"'{arg}' is not a valid positive integer")
124123
continue
125124

126125
if num < 2:

‎userland/utilities/groups.py‎

Lines changed: 1 addition & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1,7 +1,6 @@
11
import grp
22
import pwd
33
import os
4-
import sys
54

65
from .. import core
76

@@ -21,7 +20,7 @@ def python_userland_groups(_, args):
2120
user_info = pwd.getpwnam(user)
2221
except KeyError as e:
2322
failed = True
24-
print(e, file=sys.stderr)
23+
core.perror(e)
2524
continue
2625

2726
print(

‎userland/utilities/id.py‎

Lines changed: 1 addition & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1,7 +1,6 @@
11
import grp
22
import pwd
33
import os
4-
import sys
54

65
from .. import core
76

@@ -71,7 +70,7 @@ def python_userland_id(opts, args):
7170
passwd = pwd.getpwuid(int(user))
7271
except (KeyError, ValueError):
7372
failed = True
74-
print(e, file=sys.stderr)
73+
core.perror(e)
7574
continue
7675

7776
if opts.user:

‎userland/utilities/readlink.py‎

Lines changed: 2 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,3 @@
1-
import sys
21
from pathlib import Path
32
from typing import Callable
43

@@ -86,7 +85,7 @@ def python_userland_readlink(opts, args):
8685
parser.expect_nargs(args, (1,))
8786

8887
if opts.no_newline and len(args) > 1:
89-
print("ignoring --no-newline with multiple arguments", file=sys.stderr)
88+
core.perror("ignoring --no-newline with multiple arguments")
9089
opts.no_newline = False
9190

9291
# This is the precise behavior of GNU readlink regardless
@@ -103,6 +102,6 @@ def python_userland_readlink(opts, args):
103102
failed = True
104103

105104
if opts.verbose:
106-
print(e, file=sys.stderr)
105+
core.perror(e)
107106

108107
return int(failed)

‎userland/utilities/realpath.py‎

Lines changed: 1 addition & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,4 @@
11
import os
2-
import sys
32

43
from .. import core
54

@@ -116,7 +115,7 @@ def python_userland_realpath(opts, args):
116115
failed = True
117116

118117
if not opts.quiet:
119-
print(e, file=sys.stderr)
118+
core.perror(e)
120119
else:
121120
if opts.relative_to and not opts.relative_base:
122121
name = os.path.relpath(name, opts.relative_to)

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