[bash] Bash를 사용할 때 어떤 문자를 이스케이프해야합니까?

쉘 입력으로 재사용 할 수있는 형식

이 특별 printf 형식 지시자 ( %q요청 이런 종류의 내장은) :

printf [-v var] 형식 [인수]

 %q     causes printf to output the corresponding argument
        in a format that can be reused as shell input.

일부 샘플 :

read foo
Hello world
printf "%q\n" "$foo"
Hello\ world

printf "%q\n" $'Hello world!\n'
$'Hello world!\n'

변수를 통해서도 사용할 수 있습니다 :

printf -v var "%q" "$foo
"
echo "$var"
$'Hello world\n'

모든 (128) ASCII 바이트로 빠른 검사 :

128에서 255까지의 모든 바이트를 이스케이프해야합니다.

for i in {0..127} ;do
    printf -v var \\%o $i
    printf -v var $var
    printf -v res "%q" "$var"
    esc=E
    [ "$var" = "$res" ] && esc=-
    printf "%02X %s %-7s\n" $i $esc "$res"
done |
    column

이것은 다음과 같이 렌더링해야합니다.

00 E ''         1A E $'\032'    34 - 4          4E - N          68 - h
01 E $'\001'    1B E $'\E'      35 - 5          4F - O          69 - i
02 E $'\002'    1C E $'\034'    36 - 6          50 - P          6A - j
03 E $'\003'    1D E $'\035'    37 - 7          51 - Q          6B - k
04 E $'\004'    1E E $'\036'    38 - 8          52 - R          6C - l
05 E $'\005'    1F E $'\037'    39 - 9          53 - S          6D - m
06 E $'\006'    20 E \          3A - :          54 - T          6E - n
07 E $'\a'      21 E \!         3B E \;         55 - U          6F - o
08 E $'\b'      22 E \"         3C E \<         56 - V          70 - p
09 E $'\t'      23 E \#         3D - =          57 - W          71 - q
0A E $'\n'      24 E \$         3E E \>         58 - X          72 - r
0B E $'\v'      25 - %          3F E \?         59 - Y          73 - s
0C E $'\f'      26 E \&         40 - @          5A - Z          74 - t
0D E $'\r'      27 E \'         41 - A          5B E \[         75 - u
0E E $'\016'    28 E \(         42 - B          5C E \\         76 - v
0F E $'\017'    29 E \)         43 - C          5D E \]         77 - w
10 E $'\020'    2A E \*         44 - D          5E E \^         78 - x
11 E $'\021'    2B - +          45 - E          5F - _          79 - y
12 E $'\022'    2C E \,         46 - F          60 E \`         7A - z
13 E $'\023'    2D - -          47 - G          61 - a          7B E \{
14 E $'\024'    2E - .          48 - H          62 - b          7C E \|
15 E $'\025'    2F - /          49 - I          63 - c          7D E \}
16 E $'\026'    30 - 0          4A - J          64 - d          7E E \~
17 E $'\027'    31 - 1          4B - K          65 - e          7F E $'\177'
18 E $'\030'    32 - 2          4C - L          66 - f
19 E $'\031'    33 - 3          4D - M          67 - g      

첫 번째 필드가 바이트의 16 진수 값인 E경우 두 번째는 문자를 이스케이프해야하는 경우 포함 하고 세 번째 필드는 이스케이프 된 문자 표시를 표시합니다.

왜 ,?

당신은하지 않는 일부 문자를 볼 수 항상 같은 이스케이프 할 필요를 ,, }하고 {.

그래서하지 항상 하지만 언젠가 :

echo test 1, 2, 3 and 4,5.
test 1, 2, 3 and 4,5.

또는

echo test { 1, 2, 3 }
test { 1, 2, 3 }

그러나주의 :

echo test{1,2,3}
test1 test2 test3

echo test\ {1,2,3}
test 1 test 2 test 3

echo test\ {\ 1,\ 2,\ 3\ }
test  1 test  2 test  3

echo test\ {\ 1\,\ 2,\ 3\ }
test  1, 2 test  3 

답변

#!/bin/bash
special=$'`!@#$%^&*()-_+={}|[]\\;\':",.<>?/ '
for ((i=0; i < ${#special}; i++)); do
    char="${special:i:1}"
    printf -v q_char '%q' "$char"
    if [[ "$char" != "$q_char" ]]; then
        printf 'Yes - character %s needs to be escaped\n' "$char"
    else
        printf 'No - character %s does not need to be escaped\n' "$char"
    fi
done | sort

No, character % does not need to be escaped
No, character + does not need to be escaped
No, character - does not need to be escaped
No, character . does not need to be escaped
No, character / does not need to be escaped
No, character : does not need to be escaped
No, character = does not need to be escaped
No, character @ does not need to be escaped
No, character _ does not need to be escaped
Yes, character   needs to be escaped
Yes, character ! needs to be escaped
Yes, character " needs to be escaped
Yes, character # needs to be escaped
Yes, character $ needs to be escaped
Yes, character & needs to be escaped
Yes, character ' needs to be escaped
Yes, character ( needs to be escaped
Yes, character ) needs to be escaped
Yes, character * needs to be escaped
Yes, character , needs to be escaped
Yes, character ; needs to be escaped
Yes, character < needs to be escaped
Yes, character > needs to be escaped
Yes, character ? needs to be escaped
Yes, character [ needs to be escaped
Yes, character \ needs to be escaped
Yes, character ] needs to be escaped
Yes, character ^ needs to be escaped
Yes, character ` needs to be escaped
Yes, character { needs to be escaped
Yes, character | needs to be escaped
Yes, character } needs to be escaped

 !"$&'()*,:;<=>?@[\]^`{|}

#%+-.0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz~